draft-dhody-pce-stateful-pce-auto-bandwidth-06.txt   rfc8733.txt 
PCE Working Group D. Dhody Internet Engineering Task Force (IETF) D. Dhody, Ed.
Internet-Draft U. Palle Request for Comments: 8733 Huawei Technologies
Intended status: Standards Track Huawei Technologies Category: Standards Track R. Gandhi, Ed.
Expires: March 31, 2016 R. Singh ISSN: 2070-1721 Cisco Systems, Inc.
Juniper Networks U. Palle
R. Gandhi R. Singh
Cisco Systems, Inc. Individual Contributor
L. Fang L. Fang
Microsoft Expedia Group, Inc.
September 29, 2015 February 2020
PCEP Extensions for MPLS-TE LSP Automatic Bandwidth Adjustment with Path Computation Element Communication Protocol (PCEP) Extensions for
MPLS-TE Label Switched Path (LSP) Auto-Bandwidth Adjustment with
Stateful PCE Stateful PCE
draft-dhody-pce-stateful-pce-auto-bandwidth-06
Abstract Abstract
The Path Computation Element Communication Protocol (PCEP) provides The Path Computation Element Communication Protocol (PCEP) provides
mechanisms for Path Computation Elements (PCEs) to perform path mechanisms for Path Computation Elements (PCEs) to perform path
computations in response to Path Computation Clients (PCCs) requests. computations in response to Path Computation Client (PCC) requests.
The stateful PCE extensions allow stateful control of Multi-Protocol Stateful PCE extensions allow stateful control of MPLS-TE Label
Label Switching (MPLS) Traffic Engineering Label Switched Paths (TE Switched Paths (LSPs) using PCEP.
LSPs) via PCEP.
This document describes automatic bandwidth adjustment of such LSPs
when employing an Active Stateful PCE. In one of the models
described, PCC computes the bandwidth to be adjusted and informs the
PCE whereas in the second model, PCC reports the real-time bandwidth
usage to a PCE and the PCE computes the adjustment bandwidth.
This document also describes automatic bandwidth adjustment for The auto-bandwidth feature allows automatic and dynamic adjustment of
stateful PCE-initiated LSPs. the TE LSP bandwidth reservation based on the volume of traffic
flowing through the LSP. This document describes PCEP extensions for
auto-bandwidth adjustment when employing an active stateful PCE for
both PCE-initiated and PCC-initiated LSPs.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This document is a product of the Internet Engineering Task Force
Task Force (IETF). Note that other groups may also distribute (IETF). It represents the consensus of the IETF community. It has
working documents as Internet-Drafts. The list of current Internet- received public review and has been approved for publication by the
Drafts is at http://datatracker.ietf.org/drafts/current/. Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Internet-Drafts are draft documents valid for a maximum of six months Information about the current status of this document, any errata,
and may be updated, replaced, or obsoleted by other documents at any and how to provide feedback on it may be obtained at
time. It is inappropriate to use Internet-Drafts as reference https://www.rfc-editor.org/info/rfc8733.
material or to cite them other than as "work in progress."
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
2. Conventions Used in This Document . . . . . . . . . . . . . . 5 2. Conventions Used in This Document
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 5 2.1. Requirements Language
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Abbreviations
3. Requirements for PCEP Extensions . . . . . . . . . . . . . . . 6 2.3. Terminology
4. Architectural Overview . . . . . . . . . . . . . . . . . . . . 8 3. Requirements for PCEP Extensions
4.1. Auto-Bandwidth Overview . . . . . . . . . . . . . . . . . 8 4. Architectural Overview
4.2. Theory of Operation . . . . . . . . . . . . . . . . . . . 10 4.1. Auto-Bandwidth Overview
4.3. Scaling Considerations . . . . . . . . . . . . . . . . . . 11 4.2. Auto-Bandwidth Theory of Operation
5. Extensions to the PCEP . . . . . . . . . . . . . . . . . . . . 11 4.3. Scaling Considerations
5.1. AUTO-BANDWIDTH-ATTRIBUTE TLV . . . . . . . . . . . . . . . 11 5. PCEP Extensions
5.1.1. Sample-Interval sub-TLV . . . . . . . . . . . . . . . 13 5.1. Capability Advertisement
5.1.2. Adjustment-Interval sub-TLV . . . . . . . . . . . . . 13 5.1.1. AUTO-BANDWIDTH-CAPABILITY TLV
5.1.3. Adjustment Threshold . . . . . . . . . . . . . . . . . 13 5.2. AUTO-BANDWIDTH-ATTRIBUTES TLV
5.1.3.1. Adjustment-Threshold sub-TLV . . . . . . . . . . . 14 5.2.1. Sample-Interval Sub-TLV
5.1.3.2. Adjustment-Threshold-Percentage sub-TLV . . . . . 14 5.2.2. Adjustment-Intervals
5.1.4. Minimum and Maximum Bandwidth Values . . . . . . . . . 15 5.2.2.1. Adjustment-Interval Sub-TLV
5.1.4.1. Minimum-Bandwidth sub-TLV . . . . . . . . . . . . 15 5.2.2.2. Down-Adjustment-Interval Sub-TLV
5.1.4.2. Maximum-Bandwidth sub-TLV . . . . . . . . . . . . 15 5.2.3. Adjustment-Thresholds
5.1.5. Overflow and Underflow Condition . . . . . . . . . . . 16 5.2.3.1. Adjustment-Threshold Sub-TLV
5.1.5.1. Overflow-Threshold sub-TLV . . . . . . . . . . . . 16 5.2.3.2. Adjustment-Threshold-Percentage Sub-TLV
5.1.5.2. Overflow-Threshold-Percentage sub-TLV . . . . . . 17 5.2.3.3. Down-Adjustment-Threshold Sub-TLV
5.1.5.3. Underflow-Threshold sub-TLV . . . . . . . . . . . 17 5.2.3.4. Down-Adjustment-Threshold-Percentage Sub-TLV
5.1.5.4. Underflow-Threshold-Percentage sub-TLV . . . . . . 18 5.2.4. Minimum and Maximum-Bandwidth Values
5.2. BANDWIDTH-USAGE-ATTRIBUTE TLV . . . . . . . . . . . . . . 19 5.2.4.1. Minimum-Bandwidth Sub-TLV
5.2.1. Bandwidth-Usage-Report-Interval sub-TLV . . . . . . . 20 5.2.4.2. Maximum-Bandwidth Sub-TLV
5.2.2. Bandwidth-Usage-Report-Threshold sub-TLV . . . . . . . 20 5.2.5. Overflow and Underflow Conditions
5.2.3. Bandwidth-Usage-Report-Threshold-Percentage sub-TLV . 21 5.2.5.1. Overflow-Threshold Sub-TLV
5.2.4. Bandwidth-Usage-Report-Flow-Threshold sub-TLV . . . . 21 5.2.5.2. Overflow-Threshold-Percentage Sub-TLV
5.2.5. Bandwidth-Usage-Report-Flow-Threshold-Percent 5.2.5.3. Underflow-Threshold Sub-TLV
sub-TLV . . . . . . . . . . . . . . . . . . . . . . . 22 5.2.5.4. Underflow-Threshold-Percentage Sub-TLV
5.3. BANDWIDTH Object . . . . . . . . . . . . . . . . . . . . . 23 5.3. BANDWIDTH Object
5.3.1. Auto-Bandwidth Adjusted Bandwidth . . . . . . . . . . 23 5.4. The PCInitiate Message
5.3.2. Bandwidth-Usage Report . . . . . . . . . . . . . . . . 23 5.5. The PCUpd Message
5.4. The PCRpt Message . . . . . . . . . . . . . . . . . . . . 24 5.6. The PCRpt Message
5.5. The PCInitiate Message . . . . . . . . . . . . . . . . . . 24 5.7. The PCNtf Message
6. Security Considerations . . . . . . . . . . . . . . . . . . . 24 6. Manageability Considerations
7. Manageability Considerations . . . . . . . . . . . . . . . . . 24 6.1. Control of Function and Policy
7.1. Control of Function and Policy . . . . . . . . . . . . . . 24 6.2. Information and Data Models
7.2. Information and Data Models . . . . . . . . . . . . . . . 25 6.3. Liveness Detection and Monitoring
7.3. Liveness Detection and Monitoring . . . . . . . . . . . . 25 6.4. Verifying Correct Operations
7.4. Verify Correct Operations . . . . . . . . . . . . . . . . 25 6.5. Requirements for Other Protocols
7.5. Requirements On Other Protocols . . . . . . . . . . . . . 25 6.6. Impact on Network Operations
7.6. Impact On Network Operations . . . . . . . . . . . . . . . 25 7. Security Considerations
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 8. IANA Considerations
8.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . . 26 8.1. PCEP TLV Type Indicators
8.2. AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV . . . . . . . . . . . . . 26 8.2. AUTO-BANDWIDTH-CAPABILITY TLV Flag Field
8.3. BANDWIDTH-USAGE-ATTRIBUTE Sub-TLV . . . . . . . . . . . . 26 8.3. AUTO-BANDWIDTH-ATTRIBUTES Sub-TLV
8.4. BANDWIDTH Object . . . . . . . . . . . . . . . . . . . . . 27 8.4. Error Object
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27 8.5. Notification Object
9.1. Normative References . . . . . . . . . . . . . . . . . . . 27 9. References
9.2. Informative References . . . . . . . . . . . . . . . . . . 28 9.1. Normative References
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 29 9.2. Informative References
Contributors' Addresses . . . . . . . . . . . . . . . . . . . . . 29 Acknowledgments
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30 Contributors
Authors' Addresses
1. Introduction 1. Introduction
[RFC5440] describes the Path Computation Element Protocol (PCEP) as a [RFC5440] describes the Path Computation Element Protocol (PCEP) as a
communication mechanism between a Path Computation Client (PCC) and a communication mechanism between a Path Computation Client (PCC) and a
Path Control Element (PCE), or between PCE and PCE, that enables Path Computation Element (PCE), or between a PCE and a PCE, that
computation of Multi-Protocol Label Switching (MPLS) Traffic enables computation of MPLS-TE Label Switched Paths (LSPs).
Engineering Label Switched Paths (TE LSPs).
[I-D.ietf-pce-stateful-pce] specifies extensions to PCEP to enable [RFC8231] specifies extensions to PCEP to enable stateful control of
stateful control of MPLS TE LSPs. It describes two mode of MPLS-TE LSPs. It describes two modes of operation: passive stateful
operations - Passive Stateful PCE and Active Stateful PCE. In this PCE and active stateful PCE. Further, [RFC8281] describes the setup,
document, the focus is on Active Stateful PCE where LSPs are maintenance, and teardown of PCE-initiated LSPs for the stateful PCE
configured at the PCC and control over them is delegated to the PCE. model. In this document, the focus is on the active stateful PCE,
Further [I-D.ietf-pce-pce-initiated-lsp] describes the setup, where the LSPs are controlled by the PCE.
maintenance and teardown of PCE-initiated LSPs under the stateful PCE
model.
Over time, based on the varying traffic pattern, an LSP established Over time, based on the varying traffic pattern, an LSP established
with certain bandwidth may require to adjust the bandwidth, reserved with a certain bandwidth may require adjustment of the bandwidth
in the network automatically. Ingress Label Switch Router (LSR) reserved in the network dynamically. The head-end Label Switching
collects the traffic rate at each sample interval to determine the Router (LSR) monitors the actual bandwidth demand of the established
bandwidth demand of the LSP. This bandwidth information is then used LSP and periodically computes new bandwidth. The head-end LSR
to adjust the LSP bandwidth periodically. This feature is commonly automatically adjusts the bandwidth reservation of the LSP based on
referred to as Auto-Bandwidth. the computed bandwidth. This feature, when available in the head-end
LSR implementation, is commonly referred to as auto-bandwidth. The
auto-bandwidth feature is described in detail in Section 4 of this
document.
Enabling Auto-Bandwidth feature on an LSP results in the LSP In the model considered in this document, the PCC (head-end of the
automatically adjusting its bandwidth reservation based on the actual LSP) collects the traffic rate samples flowing through the LSP and
traffic flowing through the LSP. The initial LSP bandwidth can be calculates the new Adjusted Bandwidth. The PCC reports the
set to an arbitrary value (including zero), in practice, it can be calculated bandwidth to be adjusted to the PCE. This is similar to
operator expected value based on design and planning. Once the LSP the passive stateful PCE model: while the passive stateful PCE uses a
is set-up, the LSP monitors the traffic flow and adjusts its path request/reply mechanism, the active stateful PCE uses a report/
bandwidth every adjustment-interval period. The bandwidth adjustment update mechanism. With a PCE-initiated LSP, the PCC is requested
uses the make-before-break signaling method so that there is no during the LSP initiation to monitor and calculate the new Adjusted
interruption to the traffic flow. The Auto-Bandwidth is described in Bandwidth. [RFC8051] describes the use case for auto-bandwidth
detail in Section 4.1. [I-D.ietf-pce-stateful-pce-app] describes the adjustment for passive and active stateful PCEs.
use-case for Auto-Bandwidth adjustment for passive and active
stateful PCE.
In this document, following deployment models are considered for Another approach would be to send the measured values themselves to
employing Auto-Bandwidth feature with active stateful PCE. the PCE, which is considered out of scope for this document.
o Deployment model 1: PCC to decide adjusted bandwidth: This document defines the PCEP extensions needed to support an auto-
bandwidth feature in an active stateful PCE model where the LSP
bandwidth to be adjusted is calculated on the PCC (head-end of the
LSP). The use of PCE to calculate the bandwidth to be adjusted is
out of scope of this document.
* In this model, the PCC (head-end of the LSP) monitors and 2. Conventions Used in This Document
calculates the new adjusted bandwidth. The PCC reports the
calculated bandwidth to be adjusted to the PCE.
* This approach would be similar to passive stateful PCE model, 2.1. Requirements Language
while the passive stateful PCE uses path request/reply
mechanism, the active stateful PCE uses report/update mechanism
to adjust the LSP bandwidth.
* For PCE-initiated LSP, the PCC is requested during the LSP The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
initiation to monitor and calculate the new adjusted bandwidth. "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
o Deployment model 2: PCE to decide adjusted bandwidth: 2.2. Abbreviations
* In this model, the PCE calculates the new adjusted bandwidth PCC: Path Computation Client
for the LSP.
* Active stateful PCE can use information such as historical PCE: Path Computation Element
trending data, application-specific information about expected
demands and central policy information along with real-time
bandwidth usage to make smarter bandwidth adjustment to the
delegated LSPs. Since the LSP has delegated control to the
PCE, it is inherently suited that it should be the stateful PCE
that decides the bandwidth adjustments.
* For PCE-initiated LSP, the PCC is requested during initiation, PCEP: Path Computation Element Communication Protocol
to monitor and report the real-time bandwidth usage.
* This model does not exclude use of any other mechanism employed TE: Traffic Engineering
by stateful PCE to learn real-time bandwidth usage information.
But at the same time, using the same protocol (PCEP in this
case) for updating and reporting the adjustment parameters as
well as to learn real-time bandwidth usage is operationally
beneficial.
This document defines extensions needed to support Auto-Bandwidth LSP: Label Switched Path
feature on the LSPs in a active stateful PCE model using PCEP.
2. Conventions Used in This Document 2.3. Terminology
2.1. Requirements Language The reader is assumed to be familiar with the terminology defined in
[RFC5440], [RFC8231], and [RFC8281].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", In this document, the PCC is considered to be the head-end LSR of the
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this LSP. Other types of PCCs are not in scope.
document are to be interpreted as described in [RFC2119].
2.2. Terminology The following auto-bandwidth terminology is defined in this document.
The following terminology is used in this document. Maximum Average Bandwidth (MaxAvgBw): The maximum average bandwidth
represents the current 'measured' traffic bandwidth demand of the
LSP during a time interval. This is the maximum value of the
traffic bandwidth rate samples (Bandwidth-Samples) in a given time
interval.
Active Stateful PCE: PCE that uses tunnel state information learned Adjusted Bandwidth: This is the auto-bandwidth 'computed' bandwidth
from PCCs to optimize path computations. Additionally, it that is used to adjust the bandwidth reservation of the LSP.
actively updates tunnel parameters in those PCCs that delegated
control over their tunnels to the PCE.
Delegation: An operation to grant a PCE temporary rights to modify a Sample-Interval: The periodic time interval at which the measured
subset of tunnel parameters on one or more PCC's tunnels. Tunnels traffic rate of the LSP is collected as a Bandwidth-Sample.
are delegated from a PCC to a PCE.
PCC: Path Computation Client. Any client application requesting a Bandwidth-Sample: The Bandwidth-Sample of the measured traffic rate
path computation to be performed by a Path Computation Element. of the LSP collected at every Sample-Interval.
PCE: Path Computation Element. An entity (component, application, Maximum-Bandwidth: The Maximum-Bandwidth that can be reserved for
or network node) that is capable of computing a network path or the LSP.
route based on a network graph and applying computational
constraints.
TE LSP: Traffic Engineering Label Switched Path. Minimum-Bandwidth: The Minimum-Bandwidth that can be reserved for
the LSP.
Note the Auto-Bandwidth feature specific terms defined in Section Up-Adjustment-Interval: The periodic time interval at which the
4.1. bandwidth adjustment should be made using the MaxAvgBw when
MaxAvgBw is greater than the current bandwidth reservation of the
LSP.
3. Requirements for PCEP Extensions Down-Adjustment-Interval: The periodic time interval at which the
bandwidth adjustment should be made using the MaxAvgBw when
MaxAvgBw is less than the current bandwidth reservation of the
LSP.
As discussed in Section 1, there are two deployment models considered Up-Adjustment-Threshold: This parameter is used to decide when the
in this document for automatic bandwidth adjustments in case of LSP bandwidth should be adjusted. If the percentage or absolute
active stateful PCE. In the model 1, where PCC decides the adjusted difference between the current MaxAvgBw and the current bandwidth
bandwidth, PCC reports the new adjusted bandwidth and an active reservation is greater than or equal to the threshold value, the
stateful PCE updates the bandwidth of a delegated LSP via existing LSP bandwidth is adjusted (upsized) to the current bandwidth
mechanisms defined in [I-D.ietf-pce-stateful-pce]. PCEP extensions demand (Adjusted Bandwidth) at the Up-Adjustment-Interval expiry.
required for both models are summarized in the following table.
+-------------------------------------------------------------------+ Down-Adjustment-Threshold: This parameter is used to decide when the
| Model 1: PCC decides adjusted BW | LSP bandwidth should be adjusted. If the percentage or absolute
+---------------------------------+---------------------------------+ difference between the current bandwidth reservation and the
| PCC Initiated | PCE Initiated | current MaxAvgBw is greater than or equal to the threshold value,
+---------------------------------+---------------------------------+ the LSP bandwidth is adjusted (downsized) to the current bandwidth
| | | demand (Adjusted Bandwidth) at the Down-Adjustment-Interval
| PCC monitors the traffic | At the time of initiation, | expiry.
| and reports the calculated | PCE request PCC to monitor |
| bandwidth to be adjusted | the traffic and report the |
| to the PCE. | calculated bandwidth to be |
| | adjusted to the PCE. |
| | |
| No new extensions are needed. | Extension is needed for PCE |
| | to pass on the adjustment |
| | parameters at the time of |
| | Initiation. |
| | |
| Optionally AUTO-BANDWIDTH- | Refer the AUTO-BANDWIDTH- |
| ATTRIBUTE TLV can be used | ATTRIBUTE TLV (and sub-TLVs |
| to identify the LSP with | e.g. Adjustment-Interval, |
| Auto-Bandwidth Feature | Minimum-Bandwidth) in |
| enabled. | Section 5.1. |
| | |
+---------------------------------+---------------------------------+
+-------------------------------------------------------------------+ Overflow-Count: This parameter is used to decide when the LSP
| Model 2: PCC reports bandwidth-usage, PCE decides adjusted BW | bandwidth should be adjusted when there is a sudden increase in
+---------------------------------+---------------------------------+ traffic demand. This value indicates how many times,
| PCC Initiated | PCE Initiated | consecutively, that the percentage or absolute difference between
+---------------------------------+---------------------------------+ the current MaxAvgBw and the current bandwidth reservation of the
| | | LSP needs to be greater than or equal to the Overflow-Threshold
| PCC monitors bandwidth usage | At the time of initiation, | value in order to meet the overflow condition.
| and reports the real-time | PCE request PCC to monitor |
| bandwidth usage to the PCE. | the traffic and reports the |
| It is PCE that decides the | real-time bandwidth usage to |
| calculated bandwidth to be | the PCE. It is PCE that decides|
| adjusted and updates the | the calculated bandwidth to |
| LSP accordingly. | be adjusted and updates the |
| | LSP accordingly. |
| | |
| Extension is needed for | Extension is needed for PCE |
| PCC to pass on the | to pass on the real-time |
| adjustment parameters at | bandwidth usage reporting |
| the time of delegation to | parameters at the time of |
| PCE. | Initiation. |
| | |
| Refer the AUTO-BANDWIDTH- | Refer the BANDWIDTH-USAGE- |
| ATTRIBUTE TLV (and sub- | ATTRIBUTE TLV (and sub-TLVs |
| TLVs e.g. Adjustment- | e.g. Bandwidth-Usage-Report- |
| Threshold) in Section 5.1. | Interval, Bandwidth-Usage- |
| | Report-Threshold) in Section |
| | 5.2. |
| | |
| Further extension to | Further extension to report |
| report the bandwidth-usage | the bandwidth-usage to |
| to PCE are also | PCE are also needed (Refer |
| needed (Refer Bandwidth- | Bandwidth-Usage type in |
| Usage type in Section | Section 5.3.2). |
| 5.3.2). | |
| | |
+---------------------------------+---------------------------------+
Table 1: Auto-Bandwidth PCEP extensions Overflow-Threshold: This parameter is used to decide when the LSP
bandwidth should be adjusted when there is a sudden increase in
traffic demand. If the percentage or absolute difference between
the current MaxAvgBw and the current bandwidth reservation of the
LSP is greater than or equal to the threshold value, the overflow
condition is said to be met. The LSP bandwidth is adjusted to the
current bandwidth demand, bypassing the Up-Adjustment-Interval if
the overflow condition is met consecutively for the Overflow-
Count. The Overflow-Threshold needs to be greater than or equal
to the Up-Adjustment-Threshold.
Further Auto-Bandwidth deployment considerations are summarized Underflow-Count: This parameter is used to decide when the LSP
below: bandwidth should be adjusted when there is a sudden decrease in
traffic demand. This value indicates how many times,
consecutively, that the percentage or absolute difference between
the current MaxAvgBw and the current bandwidth reservation of the
LSP needs to be greater than or equal to the Underflow-Threshold
value in order to meet the underflow condition.
o It is required to identify and inform the PCEP peer, the LSP that Underflow-Threshold: This parameter is used to decide when the LSP
are enabled with Auto-Bandwidth feature. Not all LSPs in some bandwidth should be adjusted when there is a sudden decrease in
deployments would like their bandwidth to be dependent on the traffic demand. If the percentage or absolute difference between
real-time bandwidth usage but be constant as set by the operator. the current MaxAvgBw and the current bandwidth reservation of the
LSP is greater than or equal to the threshold value, the underflow
condition is said to be met. The LSP bandwidth is adjusted to the
current bandwidth demand, bypassing the Down-Adjustment-Interval
if the underflow condition is met consecutively for the Underflow-
Count. The Underflow-Threshold needs to be greater than or equal
to the Down-Adjustment-Threshold.
o It is also required to identify and inform the PCEP peer the model Minimum-Threshold: When percentage-based thresholds are in use, they
of operation i.e. if PCC decides the adjusted bandwidth, or PCC are accompanied by this Minimum-Threshold, which is used to ensure
reports the real-time bandwidth usage instead and the PCE decides that the magnitude of deviation of the calculated LSP bandwidth to
the adjusted bandwidth. be adjusted from the current bandwidth reservations exceeds a
specific non-percentage-based criterion (represented as an
absolute bandwidth value) before any adjustments are made. This
serves to suppress unnecessary auto-bandwidth adjustments and
resignaling of the LSP at low bandwidth values.
* Note that PCEP extension for reporting real-time bandwidth 3. Requirements for PCEP Extensions
usage, as specified in this document, is one of the ways for a
PCE to learn this information. But at the same time a stateful
PCE may choose to learn this information from other means like
management, performance tools, which are beyond the scope of
this document.
o Further for the LSP with Auto-Bandwidth feature enabled, an The PCEP extensions required for auto-bandwidth are summarized in the
operator should be able to specify the adjustment parameters (i.e. following table as well as in Figure 1.
configuration knobs) to control this feature (e.g. minimum/ +-------------------------+--------------------------------------+
maximum bandwidth range) and PCEP peer should be informed. | PCC Initiated | PCE Initiated |
+=========================+======================================+
| PCC monitors the | At the time of initiation, the PCE |
| traffic and reports the | requests that the PCC monitor the |
| calculated bandwidth to | traffic and report the calculated |
| be adjusted to the PCE. | bandwidth to be adjusted to the PCE. |
+-------------------------+--------------------------------------+
| Extension is needed for | Extension is needed for the PCE to |
| the PCC to pass on the | pass on the adjustment parameters at |
| adjustment parameters | the time of LSP initiation. |
| at the time of LSP | |
| delegation. | |
+-------------------------+--------------------------------------+
Table 1: Requirements for Auto-Bandwidth PCEP Extensions
----------
| |
| PCE |
| |
----------
| ^
AUTO-BANDWIDTH CAPABILITY | | AUTO-BANDWIDTH CAPABILITY
| |
AUTO-BANDWIDTH ATTRIBUTES | | AUTO-BANDWIDTH ATTRIBUTES
| | (For Delegated LSPs)
| |
| | REQUESTED BANDWIDTH
v |
----------
| |
| PCC |
| |
----------
Figure 1: Overview of Auto-Bandwidth PCEP Extensions
A PCEP speaker supporting this document must have a mechanism to
advertise the auto-bandwidth adjustment capability for both PCC-
initiated and PCE-initiated LSPs.
Auto-bandwidth deployment considerations for PCEP extensions are
summarized below:
* It is necessary to identify and inform the PCC which LSPs have
enabled the auto-bandwidth feature. Not all LSPs in some
deployments would like their bandwidth to be dependent on real-
time bandwidth usage; for some LSPs, leaving the bandwidth
constant as set by the operator is preferred.
* In addition, an operator should be able to specify the auto-
bandwidth adjustment parameters (i.e., configuration knobs) to
control this feature (e.g., Minimum/Maximum-Bandwidth range). The
PCC should be informed about these adjustment parameters.
4. Architectural Overview 4. Architectural Overview
4.1. Auto-Bandwidth Overview 4.1. Auto-Bandwidth Overview
Auto-Bandwidth feature allows an LSP to automatically and dynamically The auto-bandwidth feature allows automatic and dynamic adjustment of
adjust its reserved bandwidth over time, i.e. without network the reserved bandwidth of an LSP over time (i.e., without network
operator intervention. The bandwidth adjustment uses the operator intervention) to accommodate the varying traffic demand of
make-before-break signaling method so that there is no interruption the LSP. If the traffic flowing through the LSP is lower than the
to the traffic flow. configured or current reserved bandwidth of the LSP, the extra
bandwidth is being reserved needlessly and is being wasted.
The new bandwidth reservation is determined by sampling the actual
traffic flowing through the LSP. If the traffic flowing through the
LSP is lower than the configured or current bandwidth of the LSP, the
extra bandwidth is being reserved needlessly and being wasted.
Conversely, if the actual traffic flowing through the LSP is higher Conversely, if the actual traffic flowing through the LSP is higher
than the configured or current bandwidth of the LSP, it can than the configured or current reserved bandwidth of the LSP, it can
potentially cause congestion or packet loss in the network. With potentially cause congestion or packet loss in the network. The
Auto-Bandwidth feature, the LSP bandwidth can be set to some initial LSP bandwidth can be set to an arbitrary value (including
arbitrary value (including zero) during initial setup time, and it zero). In practice, it can be set to an expected value based on
will be periodically adjusted over time based on the actual bandwidth design and planning. The head-end LSR monitors the actual traffic
requirement. flowing through the LSP and uses that information to adjust the
bandwidth reservation of the LSP in the network.
Note the following definitions of the Auto-Bandwidth terms: Bandwidth adjustment must not cause disruption to the traffic flow
carried by the LSP. One way to achieve this is to use the make-
before-break signaling method [RFC3209].
Maximum Average Bandwidth (MaxAvgBw): The maximum average bandwidth 4.2. Auto-Bandwidth Theory of Operation
represents the current traffic bandwidth demand during a time
interval. This is the maximum value of the averaged traffic
bandwidth rate in a given adjustment-interval.
Adjusted Bandwidth: This is the Auto-Bandwidth computed bandwidth This section describes the auto-bandwidth feature in a general way.
that needs to be adjusted for the LSP. When the auto-bandwidth feature is enabled, the measured traffic rate
is periodically sampled at each Sample-Interval by the PCC when the
PCC is the head-end node of the LSP. The Sample-Interval can be
configured by an operator, with a default value of 5 minutes. A very
low Sample-Interval could have some undesirable interactions with
transport protocols (see Section 6.6).
Sample-Interval: The periodic time interval at which the traffic The traffic rate samples are accumulated over the Adjustment-Interval
rate is collected as a sample. period (in the Up or Down direction). The period can be configured
by an operator, with a default value of 24 hours. The PCC in charge
of calculating the bandwidth to be adjusted can decide to adjust the
bandwidth of the LSP to the highest traffic rate sample (MaxAvgBw)
amongst the set of Bandwidth-Samples collected over the Adjustment-
Interval period (in the Up or Down direction) depending on the
operator policy.
Bandwidth-Sample (BwSample): The bandwidth sample collected at every Note that the highest traffic rate sample could be higher or lower
sample interval to measure the traffic rate. than the current LSP bandwidth. The LSP is adjusted (upsized) to the
current bandwidth demand (MaxAvgBW) only if the difference between
the current bandwidth demand (MaxAvgBw) and the current bandwidth
reservation is greater than or equal to the Adjustment-Threshold.
The Adjustment-Threshold could be an absolute value or a percentage.
The threshold can be configured by an operator, with a default value
of 5 percent. Similarly, if the difference between the current
bandwidth reservation and the current bandwidth demand (MaxAvgBw) is
greater than or equal to the Down-Adjustment-Threshold (percentage or
absolute value), the LSP bandwidth is adjusted (downsized) to the
current bandwidth demand (MaxAvgBw). Some LSPs are less eventful,
while other LSPs may encounter a lot of changes in the traffic
pattern. The thresholds and intervals for bandwidth adjustment are
configured based on the traffic pattern of the LSP.
Adjustment-Interval: The periodic time interval at which the In order to avoid frequent resignaling, an operator may set a longer
bandwidth adjustment should be made using the MaxAvgBw. Adjustment-Interval value (Up and/or Down). However, a longer
Adjustment-Interval can result in the undesirable effect of masking
sudden changes in the traffic demands of an LSP. To avoid this, the
auto-bandwidth feature may force the Adjustment-Interval to
prematurely expire and adjust the LSP bandwidth to accommodate the
sudden bursts of increase in traffic demand as an overflow condition
or decrease in traffic demand as an underflow condition. An operator
needs to configure appropriate values for the Overflow-Threshold and/
or Underflow-Threshold parameters, and they do not have default
values defined in this document.
Maximum-Bandwidth: The maximum bandwidth that can be reserved for All thresholds in this document could be represented in both absolute
the LSP. value and percentage and could be used together. This is provided to
accommodate cases where the LSP bandwidth reservation may become very
large or very small over time. For example, an operator may use the
percentage threshold to handle small to large bandwidth values and
absolute values to handle very large bandwidth values. The auto-
bandwidth adjustment is made when either one of the two thresholds,
the absolute or percentage, is crossed.
Minimum-Bandwidth: The minimum bandwidth that can be reserved for When using the (adjustment/overflow/underflow) percentage thresholds,
the LSP. if the LSP bandwidth changes rapidly at very low values, it may
trigger frequent auto-bandwidth adjustments due to the crossing of
the percentage thresholds. This can lead to unnecessary resignaling
of the LSPs in the network. This is suppressed by setting the
Minimum-Threshold parameters along with the percentage thresholds.
The auto-bandwidth adjustment is only made if the LSP bandwidth
crosses both the percentage threshold and the Minimum-Threshold
parameters.
Adjustment-Threshold: This value is used to decide when the 4.3. Scaling Considerations
bandwidth should be adjusted. If the percentage or absolute
difference between the current MaxAvgBw and the current bandwidth
reservation is greater than or equal to the threshold value, the
LSP bandwidth is adjusted to the current bandwidth demand
(Adjusted Bandwidth) at the adjustment-interval expiry.
Overflow-Count: This value is used to decide when the bandwidth It should be noted that any bandwidth change requires resignaling of
should be adjusted when there is a sudden increase in traffic an LSP, which can further trigger preemption of lower-priority LSPs
demand. This value indicates how many times consecutively, the in the network. When deployed under scale, this can lead to a
percentage or absolute difference between the current MaxAvgBw and signaling churn in the network. The auto-bandwidth application
the current bandwidth reservation is greater than or equal to the algorithm is thus advised to take this into consideration before
Overflow-Threshold value. adjusting the LSP bandwidth. Operators are advised to set the values
of various auto-bandwidth adjustment parameters appropriate for the
deployed LSP scale.
Overflow-Threshold: This value is used to decide when the bandwidth If a PCE gets overwhelmed, it can notify the PCC to temporarily
should be adjusted when there is a sudden increase in traffic suspend the reporting of the new LSP bandwidth to be adjusted.
demand. If the percentage or absolute difference between the Similarly, if a PCC gets overwhelmed due to signaling churn, it can
current MaxAvgBw and the current bandwidth reservation is greater notify the PCE to temporarily suspend new LSP setup requests. See
than or equal to the threshold value, the overflow-condition is Section 5.7 of this document.
set to be met. The LSP bandwidth is adjusted to the current
bandwidth demand bypassing the adjustment-interval if the
overflow-condition is met consecutively for the Overflow-Count.
Underflow-Count: This value is used to decide when the bandwidth 5. PCEP Extensions
should be adjusted when there is a sudden decrease in traffic
demand. This value indicates how many times consecutively, the
percentage or absolute difference between the current MaxAvgBw and
the current bandwidth reservation is greater than or equal to the
Underflow-Threshold value.
Underflow-Threshold: This value is used to decide when the bandwidth 5.1. Capability Advertisement
should be adjusted when there is a sudden decrease in traffic
demand. If the percentage or absolute difference between the
current MaxAvgBw and the current bandwidth reservation is greater
than or equal to the threshold value, the underflow-condition is
set to be met. The LSP bandwidth is adjusted to the current
bandwidth demand bypassing the adjustment-interval if the
underflow-condition is met consecutively for the Underflow-Count.
Report-Interval: This value indicates the periodic interval when the During the PCEP initialization phase, PCEP speakers (PCE or PCC)
collected real-time bandwidth-usage samples (BwSample) should be advertise their support of the auto-bandwidth adjustment feature. A
reported to the stateful PCE via the PCRpt message. PCEP speaker includes the AUTO-BANDWIDTH-CAPABILITY TLV in the OPEN
object to advertise its support for PCEP auto-bandwidth extensions.
The presence of the AUTO-BANDWIDTH-CAPABILITY TLV in the OPEN object
indicates that the auto-bandwidth feature is supported as described
in this document.
Report-Threshold: This value is used to decide if the real-time * The PCEP protocol extensions for auto-bandwidth adjustments MUST
bandwidth-usage samples collected should be reported. Only if the NOT be used if one or both PCEP speakers have not included the
percentage or the absolute difference between at least one of the AUTO-BANDWIDTH-CAPABILITY TLV in their respective OPEN message.
bandwidth samples collected and the current bandwidth reservation
is greater than or equal to the threshold value, the bandwidth
samples collected during the Report-Interval are reported
otherwise the bandwidth sample(s) are skipped.
Report-Flow-Threshold: This value is used to decide when the real- * A PCEP speaker that does not recognize the extensions defined in
time traffic bandwidth samples should be reported immediately when this document would simply ignore the TLVs as per [RFC5440].
there is a sudden change in traffic demand. If the percentage or
absolute difference between the current bandwidth sample and the
current bandwidth reservation is greater than or equal to the
flow-threshold value, all the bandwidth samples collected so far
are reported to the PCE immediately.
4.2. Theory of Operation * If a PCEP speaker supports the extensions defined in this document
but did not advertise this capability, then upon receipt of AUTO-
BANDWIDTH-ATTRIBUTES TLV in the LSP Attributes (LSPA) object, it
SHOULD generate a PCErr with Error-Type 19 (Invalid Operation) and
Error-value 14 (Auto-Bandwidth capability was not advertised) and
ignore the AUTO-BANDWIDTH-ATTRIBUTES TLV.
The traffic rate is periodically sampled at each sample-interval 5.1.1. AUTO-BANDWIDTH-CAPABILITY TLV
(which can be configured by the user and the default value as 5
minutes) by the head-end node of the LSP. The sampled traffic rates
are accumulated over the adjustment-interval period (which can be
configured by the user and the default value as 24 hours). The PCEP
peer which is in-charge of calculating the bandwidth to be adjusted,
will adjust the bandwidth of the LSP to the highest sampled traffic
rate (MaxAvgBw) amongst the set of bandwidth samples collected over
the adjustment-interval.
Note that the highest sampled traffic rate could be higher or lower The AUTO-BANDWIDTH-CAPABILITY TLV is an optional TLV for use in the
than the current LSP bandwidth. Only if the difference between the OPEN Object for auto-bandwidth adjustment via PCEP capability
current bandwidth demand (MaxAvgBw) and the current bandwidth advertisement. Its format is shown in the following figure:
reservation is greater than or equal to the Adjustment-Threshold
(percentage or absolute value), the LSP bandwidth is adjusted to the
current bandwidth demand (MaxAvgBw). Some LSPs are less eventful
while other LSPs may encounter a lot of changes in the traffic
pattern. PCE sets the intervals for reporting and adjustment based
on the traffic pattern of the LSP.
In order to avoid frequent re-signaling, an operator may set a longer 0 1 2 3
adjustment-interval value. However, longer adjustment-interval can 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
result in an undesirable effect of masking sudden changes in traffic +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
demands of an LSP. To avoid this, the Auto-Bandwidth feature may | Type=36 | Length=4 |
pre-maturely expire the adjustment-interval and adjust the LSP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
bandwidth to accommodate the sudden bursts of increase in traffic | Flag |
demand as an overflow condition or decrease in traffic demand as an +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
underflow condition.
In case of Deployment model 2, the PCC reports the real-time Figure 2: AUTO-BANDWIDTH-CAPABILITY TLV Format
bandwidth-usage information and the PCE decides the adjusted
bandwidth. Multiple bandwidth samples are collected every report-
interval, and reported together to the PCE. To avoid reporting minor
changes in real-time bandwidth-usage, report-threshold is used, to
suppress the sending of the collected samples during the report-
interval. The collected samples are reported if at least one sample
crosses the Report-Threshold (percentage or absolute value). In
order to accommodate sudden changes in the bandwidth usage, report-
flow-threshold is employed by pre-maturely expiry of the report-
interval to report the unreported bandwidth samples collected so far.
All thresholds in this document could be represented in both absolute The TLV Type is 36, and it has a fixed Length of 4 octets.
value and percentage, and could be used together.
4.3. Scaling Considerations The value comprises a single field: Flag (32 bits). No flags are
defined for this TLV in this document.
There are potential scaling concerns for the model where PCC (ingress Unassigned bits are considered reserved. They MUST be set to 0 on
LSR) reports real-time bandwidth-usage information to the stateful transmission and MUST be ignored on receipt.
PCE for a large number of LSPs. It is recommended to combine
multiple bandwidth samples (BwSamples) using larger report-interval
and report them together to the PCE, thus reducing the number of
PCRpt messages. Further Report-Threshold can be use to skip
reporting the bandwidth samples for small changes in the bandwidth.
The processing cost of monitoring a large number of LSPs at the PCC Advertisement of the AUTO-BANDWIDTH-CAPABILITY TLV implies support of
and handling bandwidth change requests at PCE should be taken into auto-bandwidth adjustment, as well as the objects, TLVs, and
consideration. Note that, this will be implementation dependent. procedures defined in this document.
5. Extensions to the PCEP 5.2. AUTO-BANDWIDTH-ATTRIBUTES TLV
5.1. AUTO-BANDWIDTH-ATTRIBUTE TLV The AUTO-BANDWIDTH-ATTRIBUTES TLV provides the 'configurable knobs'
of the feature, and it can be included as an optional TLV in the LSPA
object (as described in [RFC5440]).
The AUTO-BANDWIDTH-ATTRIBUTE TLV can be included as an optional TLV For a PCE-initiated LSP [RFC8281], this TLV is included in the LSPA
in the LSPA Object (as described in [RFC5440]). Whenever the LSP object with the PCInitiate message. For the PCC-initiated delegated
with Auto-Bandwidth feature enabled is delegated, LSPs, this TLV is carried in the Path Computation State Report
AUTO-BANDWIDTH-ATTRIBUTE TLV is carried in PCRpt message in LSPA (PCRpt) message in the LSPA object. This TLV is also carried in the
Object. The TLV provides PCE with the 'configurable knobs' of this LSPA object with the Path Computation Update Request (PCUpd) message
feature. In case of PCE-Initiated LSP to direct the PCC (LSP head-end) to make updates to auto-bandwidth
([I-D.ietf-pce-pce-initiated-lsp]) with Auto-Bandwidth feature attributes such as Adjustment-Interval.
enabled, this TLV is included in LSPA Object with PCInitiate message.
The format of the AUTO-BANDWIDTH-ATTRIBUTE TLV is shown in the The TLV is encoded in all PCEP messages for the LSP while the auto-
bandwidth adjustment feature is enabled. The absence of the TLV
indicates the PCEP speaker wishes to disable the feature. This TLV
includes multiple AUTO-BANDWIDTH-ATTRIBUTES sub-TLVs. The AUTO-
BANDWIDTH-ATTRIBUTES sub-TLVs are included if there is a change since
the last information sent in the PCEP message. The default values
for missing sub-TLVs apply for the first PCEP message for the LSP.
The format of the AUTO-BANDWIDTH-ATTRIBUTES TLV is shown in the
following figure: following figure:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=[TBD1] | Length | | Type=37 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// sub-TLVs // // sub-TLVs //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
AUTO-BANDWIDTH-ATTRIBUTE TLV format Figure 3: AUTO-BANDWIDTH-ATTRIBUTES TLV Format
Type: TBD1
Length: Variable
Value: This comprises one or more sub-TLVs.
Following sub-TLVs are defined in this document: Type: 37
Type Len Name Length: The Length field defines the length of the value portion in
------------------------------------------------------------------- bytes as per [RFC5440].
1 4 Sample-Interval sub-TLV
2 4 Adjustment-Interval sub-TLV
3 4 Adjustment-Threshold sub-TLV
4 4 Adjustment-Threshold-Percentage sub-TLV
5 4 Minimum-Bandwidth sub-TLV
6 4 Maximum-Bandwidth sub-TLV
7 8 Overflow-Threshold sub-TLV
8 4 Overflow-Threshold-Percentage sub-TLV
9 8 Underflow-Threshold sub-TLV
10 4 Underflow-Threshold-Percentage sub-TLV
Future specification can define additional sub-TLVs. Value: This comprises one or more sub-TLVs.
The presence of AUTO-BANDWIDTH-ATTRIBUTE TLV in LSPA Object means The following sub-TLVs are defined in this document:
that the automatic bandwidth adjustment feature is enabled. All
sub-TLVs are optional and any unrecognized sub-TLV MUST be silently
ignored. If a sub-TLV of same type appears more than once, only the
first occurrence is processed and all others MUST be ignored.
The AUTO-BANDWIDTH-ATTRIBUTE TLV can also be carried in PCUpd message +------+-----+--------------------------------------+
in LSPA Object in order to make updates to auto-bandwidth attributes | Type | Len | Name |
such as Adjustment-Interval. +======+=====+======================================+
| 1 | 4 | Sample-Interval |
+------+-----+--------------------------------------+
| 2 | 4 | Adjustment-Interval |
+------+-----+--------------------------------------+
| 3 | 4 | Down-Adjustment-Interval |
+------+-----+--------------------------------------+
| 4 | 4 | Adjustment-Threshold |
+------+-----+--------------------------------------+
| 5 | 8 | Adjustment-Threshold-Percentage |
+------+-----+--------------------------------------+
| 6 | 4 | Down-Adjustment-Threshold |
+------+-----+--------------------------------------+
| 7 | 8 | Down-Adjustment-Threshold-Percentage |
+------+-----+--------------------------------------+
| 8 | 4 | Minimum-Bandwidth |
+------+-----+--------------------------------------+
| 9 | 4 | Maximum-Bandwidth |
+------+-----+--------------------------------------+
| 10 | 8 | Overflow-Threshold |
+------+-----+--------------------------------------+
| 11 | 8 | Overflow-Threshold-Percentage |
+------+-----+--------------------------------------+
| 12 | 8 | Underflow-Threshold |
+------+-----+--------------------------------------+
| 13 | 8 | Underflow-Threshold-Percentage |
+------+-----+--------------------------------------+
If sub-TLVs are not present, the default values based on the local Table 2: Sub-TLV Types of the AUTO-BANDWIDTH-
policy are assumed. ATTRIBUTES TLV
The sub-TLVs are encoded to inform the PCEP peer the various sampling Future specifications can define additional sub-TLVs.
and adjustment parameters, and serves the following purpose -
o For PCE-Initiated LSPs, inform the PCC of the various sampling and The sub-TLVs are encoded to inform the PCEP peer of the various
adjustment parameters. sampling and adjustment parameters. In the case of a missing sub-
TLV, as per the local policy, either the default value (as specified
in this document) or some other operator-configured value is used.
o For PCC-Initiated LSPs in the Deployment Model 2 (where PCE All sub-TLVs are optional, and any unrecognized sub-TLV MUST be
decides the adjusted bandwidth), inform the PCE of the various ignored. If a sub-TLV of the same type appears more than once, only
sampling and adjustment parameters. the first occurrence is processed, and all others MUST be ignored.
The following sub-sections describe the sub-TLVs which are currently The following subsections describe the sub-TLVs that are currently
defined to be carried within the AUTO-BANDWIDTH-ATTRIBUTE TLV. defined as being carried within the AUTO-BANDWIDTH-ATTRIBUTES TLV.
5.1.1. Sample-Interval sub-TLV 5.2.1. Sample-Interval Sub-TLV
The Sample-Interval sub-TLV specifies a time interval in seconds at The Sample-Interval sub-TLV specifies a time interval in seconds in
which traffic samples are collected at the PCC. which traffic samples are collected at the PCC.
The Type is 1, Length is 4, and the value comprises of 4-octet time
interval, the valid range is from 1 to 604800, in seconds. The
default value is 300 seconds.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=1 | Length=4 | | Type=1 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sample-Interval | | Sample-Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sample-Interval sub-TLV format Figure 4: Sample-Interval Sub-TLV Format
5.1.2. Adjustment-Interval sub-TLV The Type is 1, the Length is 4 octets, and the value comprises the
following:
The Adjustment-Interval sub-TLV specifies a time interval in seconds Sample-Interval: The 4-octet time interval for the Bandwidth-Sample
at which bandwidth adjustment should be made. collection. The valid range is from 1 to 604800 (7 days), in
seconds. The default value is 300 seconds. Due care needs to be
taken in a case with a very low Sample-Interval, as it can have
some undesirable interactions with transport protocols (see
Section 6.6). The Sample-Interval parameter MUST NOT be greater
than the (down) Adjustment-Interval. In the case in which an
invalid value is present, the sub-TLV MUST be ignored and the
previous value will be maintained.
The Type is 2, Length is 4, and the value comprises of 4-octet time 5.2.2. Adjustment-Intervals
interval, the valid range is from 1 to 604800, in seconds. The
default value is 300 seconds. The sub-TLVs in this section are encoded to inform the PCEP peer of
the Adjustment-Interval parameters. The Adjustment-Interval sub-TLV
specifies the time interval for both upward (Up-Adjustment-Interval)
and downward (Down-Adjustment-Interval) trends. An implementation
MAY require that a different Adjustment-Interval value be set when
the bandwidth usage trend is moving downwards from the one used when
it is moving upwards. In that case, the operator could use the Down-
Adjustment-Interval sub-TLV, which overrides the Adjustment-Interval
value for Down-Adjustment-Interval.
5.2.2.1. Adjustment-Interval Sub-TLV
The Adjustment-Interval sub-TLV specifies a time interval in seconds
in which a bandwidth adjustment should be made in an upward or
downward direction. This sub-TLV specifies the value for Up-
Adjustment-Interval and Down-Adjustment-Interval when they are the
same and when the Down-Adjustment-Interval sub-TLV is not included.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=2 | Length=4 | | Type=2 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Adjustment-Interval | | Adjustment-Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Adjustment-Interval sub-TLV format Figure 5: Adjustment-Interval Sub-TLV Format
5.1.3. Adjustment Threshold The Type is 2, the Length is 4 octets, and the value comprises the
following:
The sub-TLVs in this section are encoded to inform the PCEP peer the Adjustment-Interval: The 4-octet time interval for bandwidth
adjustment threshold parameters. An implementation MAY include both adjustments. The valid range is from 1 to 604800 (7 days), in
sub-TLVs for the absolute value and the percentage, in which case the seconds. The default value is 86400 seconds (1 day). The
bandwidth is adjusted when either of the adjustment threshold Adjustment-Interval parameter MUST NOT be less than the Sample-
conditions are met. Interval; otherwise, the sub-TLV MUST be ignored, and the previous
value will be maintained.
5.1.3.1. Adjustment-Threshold sub-TLV 5.2.2.2. Down-Adjustment-Interval Sub-TLV
The Adjustment-Threshold sub-TLV is used to decide when the LSP The Down-Adjustment-Interval sub-TLV specifies a time interval in
bandwidth should be adjusted. seconds in which a bandwidth adjustment should be made when MaxAvgBw
is less than the current bandwidth reservation of the LSP. This
parameter overrides the Adjustment-Interval for the downward trend.
This sub-TLV is used only when there is a need for different
Adjustment-Intervals in the upward and downward directions.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=3 | Length=4 | | Type=3 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Adjustment Threshold | | Down-Adjustment-Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Adjustment-Threshold sub-TLV format Figure 6: Down-Adjustment-Interval Sub-TLV Format
The Type is 3, Length is 4, and the value comprises of - The Type is 3, the Length is 4 octets, and the value comprises the
following:
o Adjustment Threshold: The absolute Adjustment-Threshold bandwidth Down-Adjustment-Interval: The 4-octet time interval for downward
value, encoded in IEEE floating point format (see bandwidth adjustments. The valid range is from 1 to 604800 (7
[IEEE.754.1985]), expressed in bytes per second. Refer to Section days), in seconds. The default value equals the Adjustment-
3.1.2 of [RFC3471] for a table of commonly used values. Interval. The Down-Adjustment-Interval parameter MUST NOT be less
than the Sample-Interval; otherwise, the sub-TLV MUST be ignored
and the previous value will be maintained.
If the difference between the current MaxAvgBw and the current 5.2.3. Adjustment-Thresholds
bandwidth reservation is greater than or equal to the threshold
value, the LSP bandwidth is adjusted to the current bandwidth
demand.
5.1.3.2. Adjustment-Threshold-Percentage sub-TLV The sub-TLVs in this section are encoded to inform the PCEP peer of
the Adjustment-Threshold parameters. An implementation MAY include
both sub-TLVs for the absolute value and the percentage, in which
case the bandwidth is adjusted when either of the Adjustment-
Threshold conditions are met. The Adjustment-Threshold sub-TLV
specifies the threshold for both upward (Up-Adjustment-Threshold) and
downward (Down-Adjustment-Threshold) trends. If the operator would
like to use a different Adjustment-Threshold during the downward
trend, the Down-Adjustment-Threshold sub-TLV is included. Similarly,
the Adjustment-Threshold-Percentage sub-TLV specifies the threshold
percentage for both upward and downward trends. If the operator
would like to use a different Adjustment-Threshold percentage during
the downward trend, the Down-Adjustment-Threshold-Percentage sub-TLV
is included. It is worth noting that regardless of how the
thresholds are set, the adjustment will not be made until at least
one Sample-Interval has passed simply because no sample will be made
on which to base a comparison with a threshold.
The Adjustment-Threshold-Percentage sub-TLV is used to decide when 5.2.3.1. Adjustment-Threshold Sub-TLV
the LSP bandwidth should be adjusted.
The Adjustment-Threshold sub-TLV is used to decide when the LSP
bandwidth should be adjusted in an upward or downward direction.
This sub-TLV specifies the absolute value for Up-Adjustment-Threshold
and Down-Adjustment-Threshold when they are the same and when the
Down-Adjustment-Threshold sub-TLV is not included.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=4 | Length=4 | | Type=4 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Percentage | | Adjustment-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Adjustment-Threshold-Percentage sub-TLV format Figure 7: Adjustment-Threshold Sub-TLV Format
The Type is 4, Length is 4, and the value comprises of - The Type is 4, the Length is 4 octets, and the value comprises the
o Reserved: SHOULD be set to zero on transmission and MUST be following:
ignored on receipt.
o Percentage: The Adjustment-Threshold value, encoded in percentage Adjustment-Threshold: The absolute Adjustment-Threshold bandwidth
(an integer from 0 to 100). If the percentage difference between difference value, encoded in IEEE floating point format (see
the current MaxAvgBw and the current bandwidth reservation is [IEEE.754.1985]) and expressed in bytes per second. The default
greater than or equal to the threshold percentage, the LSP Adjustment-Threshold value is not set. Refer to Section 3.1.2 of
bandwidth is adjusted to the current bandwidth demand. [RFC3471] for a table of commonly used values.
5.1.4. Minimum and Maximum Bandwidth Values If the modulus of difference between the current MaxAvgBw and the
current bandwidth reservation is greater than or equal to the
threshold value, the LSP bandwidth is adjusted to the current
bandwidth demand (MaxAvgBw).
5.1.4.1. Minimum-Bandwidth sub-TLV In the case in which an invalid value is present, the sub-TLV MUST be
ignored and the previous value will be maintained.
The Minimum-Bandwidth sub-TLV specify the minimum bandwidth allowed 5.2.3.2. Adjustment-Threshold-Percentage Sub-TLV
for the LSP, and is expressed in bytes per second. The LSP bandwidth
cannot be adjusted below the minimum bandwidth value.
The Type is 5, Length is 4, and the value comprises of 4-octet The Adjustment-Threshold-Percentage sub-TLV is used to decide when
bandwidth value encoded in IEEE floating point format (see the LSP bandwidth should be adjusted in an upward or downward
[IEEE.754.1985]), expressed in bytes per second. Refer to Section direction. This sub-TLV specifies the percentage value for Up-
3.1.2 of [RFC3471] for a table of commonly used values. Adjustment-Threshold and Down-Adjustment-Threshold when they are the
same and when the Down-Adjustment-Threshold-Percentage sub-TLV is not
included.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=5 | Length=4 | | Type=5 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum-Bandwidth | | Reserved | Percentage |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Minimum-Bandwidth sub-TLV format Figure 8: Adjustment-Threshold-Percentage Sub-TLV Format
5.1.4.2. Maximum-Bandwidth sub-TLV The Type is 5, the Length is 8 octets, and the value comprises the
following:
The Maximum-Bandwidth sub-TLV specify the maximum bandwidth allowed Reserved: MUST be set to zero on transmission and MUST be ignored on
for the LSP, and is expressed in bytes per second. The LSP bandwidth receipt.
cannot be adjusted above the maximum bandwidth value.
The Type is 6, Length is 4, and the value comprises of 4-octet Percentage: The Adjustment-Threshold value (7 bits), encoded in a
bandwidth value encoded in IEEE floating point format (see percentage (an integer from 1 to 100). The value 0 is considered
[IEEE.754.1985]), expressed in bytes per second. Refer to Section to be invalid. The default value is 5 percent.
3.1.2 of [RFC3471] for a table of commonly used values.
Minimum-Threshold: The absolute Minimum-Threshold bandwidth value,
encoded in IEEE floating point format (see [IEEE.754.1985]) and
expressed in bytes per second. The increase or decrease of the
LSP bandwidth MUST be at or above the Minimum-Threshold before the
bandwidth adjustment is made. The default value is 0.
If the percentage absolute difference between the current MaxAvgBw
and the current bandwidth reservation is greater than or equal to the
threshold percentage and the difference in the bandwidth is at or
above the Minimum-Threshold, the LSP bandwidth is adjusted to the
current bandwidth demand (MaxAvgBw).
In the case in which an invalid value is present, the sub-TLV MUST be
ignored and the previous value will be maintained.
5.2.3.3. Down-Adjustment-Threshold Sub-TLV
The Down-Adjustment-Threshold sub-TLV is used to decide when the LSP
bandwidth should be adjusted when MaxAvgBw is less than the current
bandwidth reservation. This parameter overrides the Adjustment-
Threshold for the downward trend. This sub-TLV is used only when
there is a need for a different threshold in the upward and downward
directions.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=6 | Length=4 | | Type=6 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum-Bandwidth | | Down-Adjustment-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Maximum-Bandwidth sub-TLV format Figure 9: Down-Adjustment-Threshold Sub-TLV Format
5.1.5. Overflow and Underflow Condition The Type is 6, the Length is 4 octets, and the value comprises the
following:
The sub-TLVs in this section are encoded to inform the PCEP peer the Down-Adjustment-Threshold: The absolute Down-Adjustment-Threshold
overflow and underflow threshold parameters. An implementation MAY bandwidth value, encoded in IEEE floating point format (see
include sub-TLVs for the absolute value and the percentage for the [IEEE.754.1985]) and expressed in bytes per second. The default
threshold, in which case the bandwidth is immediately adjusted when value equals the Adjustment-Threshold. Refer to Section 3.1.2 of
either of the adjustment threshold conditions are met consecutively [RFC3471] for a table of commonly used values.
for the given count.
5.1.5.1. Overflow-Threshold sub-TLV If the difference between the current bandwidth reservation and the
current MaxAvgBw is greater than or equal to the threshold value, the
LSP bandwidth is adjusted to the current bandwidth demand (MaxAvgBw).
The Overflow-Threshold sub-TLV is used to decide if the bandwidth In the case in which an invalid value is present, the sub-TLV MUST be
should be adjusted immediately. ignored and the previous value will be maintained.
5.2.3.4. Down-Adjustment-Threshold-Percentage Sub-TLV
The Down-Adjustment-Threshold-Percentage sub-TLV is used to decide
when the LSP bandwidth should be adjusted when MaxAvgBw is less than
the current bandwidth reservation. This parameter overrides the
Adjustment-Threshold-Percentage for the downward trend. This sub-TLV
is used only when there is a need for a different threshold
percentage in the upward and downward directions.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=7 | Length=8 | | Type=7 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Count | | Reserved | Percentage |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Overflow Threshold | | Minimum-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Overflow-Threshold sub-TLV format Figure 10: Down-Adjustment-Threshold-Percentage Sub-TLV Format
The Type is 7, Length is 4, and the value comprises of - The Type is 7, the Length is 8 octets, and the value comprises the
following:
o Reserved: SHOULD be set to zero on transmission and MUST be Reserved: MUST be set to zero on transmission and MUST be ignored on
ignored on receipt. receipt.
o Count: The Overflow-Count value, encoded in integer. The value 0 Percentage: The Down-Adjustment-Threshold value (7 bits), encoded in
is considered to be invalid. The number of consecutive samples a percentage (an integer from 1 to 100). The value 0 is
for which the overflow condition MUST be met for the LSP bandwidth considered to be invalid. The default value equals the
to be immediately adjusted to the current bandwidth demand, Adjustment-Threshold-Percentage.
bypassing the adjustment-interval.
o Overflow Threshold: The absolute Overflow-Threshold bandwidth Minimum-Threshold: The absolute Minimum-Threshold bandwidth value,
value, encoded in IEEE floating point format (see encoded in IEEE floating point format (see [IEEE.754.1985]) and
[IEEE.754.1985]), expressed in bytes per second. Refer to Section expressed in bytes per second. The decrease of the LSP bandwidth
3.1.2 of [RFC3471] for a table of commonly used values. If the MUST be at or above the Minimum-Threshold before the bandwidth
increase of the current MaxAvgBw from the current bandwidth adjustment is made. The default value equals the Minimum-
reservation is greater than or equal to the threshold value, the Threshold for the Adjustment-Threshold-Percentage.
overflow condition is met.
5.1.5.2. Overflow-Threshold-Percentage sub-TLV If the percentage difference between the current bandwidth
reservation and the current MaxAvgBw is greater than or equal to the
threshold percentage and the difference in the bandwidth is at or
above the Minimum-Threshold, the LSP bandwidth is adjusted to the
current bandwidth demand (MaxAvgBw).
The Overflow-Threshold-Percentage sub-TLV is used to decide if the In the case in which an invalid value is present, the sub-TLV MUST be
bandwidth should be adjusted immediately. ignored and the previous value will be maintained.
5.2.4. Minimum and Maximum-Bandwidth Values
5.2.4.1. Minimum-Bandwidth Sub-TLV
The Minimum-Bandwidth sub-TLV specifies the Minimum-Bandwidth allowed
for the LSP and is expressed in bytes per second. The LSP bandwidth
cannot be adjusted below the Minimum-Bandwidth value.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=8 | Length=4 | | Type=8 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Percentage | Reserved | Count | | Minimum-Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Overflow-Threshold-Percentage sub-TLV format Figure 11: Minimum-Bandwidth Sub-TLV Format
The Type is 8, Length is 4, and the value comprises of -
o Percentage: The Overflow-Threshold value, encoded in percentage The Type is 8, the Length is 4 octets, and the value comprises the
(an integer from 0 to 100). If the percentage increase of the following:
current MaxAvgBw from the current bandwidth reservation is greater
than or equal to the threshold percentage, the overflow condition
is met.
o Reserved: SHOULD be set to zero on transmission and MUST be Minimum-Bandwidth: The 4-octet bandwidth value encoded in IEEE
ignored on receipt. floating point format (see [IEEE.754.1985]) and expressed in bytes
per second. The default Minimum-Bandwidth value is set to 0.
Refer to Section 3.1.2 of [RFC3471] for a table of commonly used
values.
o Count: The Overflow-Count value, encoded in integer. The value 0 In the case in which an invalid value is present, the sub-TLV MUST be
is considered to be invalid. The number of consecutive samples ignored and the previous value will be maintained.
for which the overflow condition MUST be met for the LSP bandwidth
to be immediately adjusted to the current bandwidth demand,
bypassing the adjustment-interval.
5.1.5.3. Underflow-Threshold sub-TLV 5.2.4.2. Maximum-Bandwidth Sub-TLV
The Underflow-Threshold sub-TLV is used to decide if the bandwidth The Maximum-Bandwidth sub-TLV specifies the Maximum-Bandwidth allowed
should be adjusted immediately. for the LSP and is expressed in bytes per second. The LSP bandwidth
cannot be adjusted above the Maximum-Bandwidth value.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=9 | Length=8 | | Type=9 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Underflow Threshold | | Maximum-Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Underflow-Threshold sub-TLV format Figure 12: Maximum-Bandwidth Sub-TLV Format
The Type is 9, Length is 8, and the value comprises of - The Type is 9, the Length is 4 octets, and the value comprises the
following:
o Reserved: SHOULD be set to zero on transmission and MUST be Maximum-Bandwidth: The 4-octet bandwidth value encoded in IEEE
ignored on receipt. floating point format (see [IEEE.754.1985]) and expressed in bytes
per second. The default Maximum-Bandwidth value is not set.
Refer to Section 3.1.2 of [RFC3471] for a table of commonly used
values.
o Count: The Underflow-Count value, encoded in integer. The value 0 In the case in which an invalid value is present, the sub-TLV MUST be
is considered to be invalid. The number of consecutive samples ignored and the previous value will be maintained.
for which the underflow condition MUST be met for the LSP
bandwidth to be immediately adjusted to the current bandwidth
demand, bypassing the adjustment-interval.
o Underflow Threshold: The absolute Underflow-Threshold bandwidth 5.2.5. Overflow and Underflow Conditions
value, encoded in IEEE floating point format (see
[IEEE.754.1985]), expressed in bytes per second. Refer to Section
3.1.2 of [RFC3471] for a table of commonly used values. If the
decrease of the current MaxAvgBw from the current bandwidth
reservation is greater than or equal to the threshold value, the
underflow condition is met.
5.1.5.4. Underflow-Threshold-Percentage sub-TLV The sub-TLVs in this section are encoded to inform the PCEP peer of
the overflow and underflow threshold parameters. An implementation
MAY include sub-TLVs for an absolute value and/or a percentage for
the threshold, in which case the bandwidth is immediately adjusted
when either of the threshold conditions is met consecutively for the
given count (as long as the difference in the bandwidth is at or
above the Minimum-Threshold). By default, the threshold values for
overflow and underflow conditions are not set.
The Underflow-Threshold-Percentage sub-TLV is used to decide if the 5.2.5.1. Overflow-Threshold Sub-TLV
bandwidth should be adjusted immediately.
The Overflow-Threshold sub-TLV is used to decide if the LSP bandwidth
should be adjusted immediately.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=10 | Length=4 | | Type=10 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Percentage | Reserved | Count | | Reserved | Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Overflow-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Underflow-Threshold-Percentage sub-TLV format Figure 13: Overflow-Threshold Sub-TLV Format
The Type is 10, Length is 4, and the value comprises of - The Type is 10, the Length is 8 octets, and the value comprises the
following:
o Percentage: The Underflow-Threshold value, encoded in percentage Reserved: MUST be set to zero on transmission and MUST be ignored on
(an integer from 0 to 100). If the percentage decrease of the receipt.
current MaxAvgBw from the current bandwidth reservation is greater
than or equal to the threshold percentage, the underflow condition
is met.
o Reserved: SHOULD be set to zero on transmission and MUST be Count: The Overflow-Count value (5 bits), encoded in an integer.
ignored on receipt. The value 0 is considered to be invalid. The number of
consecutive samples for which the overflow condition MUST be met
for the LSP bandwidth is to be immediately adjusted to the current
bandwidth demand, bypassing the (up) Adjustment-Interval.
o Count: The Underflow-Count value, encoded in integer. The value 0 Overflow-Threshold: The absolute Overflow-Threshold bandwidth value,
is considered to be invalid. The number of consecutive samples encoded in IEEE floating point format (see [IEEE.754.1985]) and
for which the underflow condition MUST be met for the LSP expressed in bytes per second. Refer to Section 3.1.2 of
bandwidth to be immediately adjusted to the current bandwidth [RFC3471] for a table of commonly used values. If the difference
demand, bypassing the adjustment-interval. between the current MaxAvgBw and the current bandwidth reservation
is greater than or equal to the threshold value, the overflow
condition is met.
5.2. BANDWIDTH-USAGE-ATTRIBUTE TLV In the case in which an invalid value is present, the sub-TLV MUST be
ignored and the previous value will be maintained.
The BANDWIDTH-USAGE-ATTRIBUTE TLV can be included as an optional TLV 5.2.5.2. Overflow-Threshold-Percentage Sub-TLV
in the LSPA Object (as described in [RFC5440]). Whenever the LSP
Bandwidth Usage needs to be reported to the PCE, the BANDWIDTH-USAGE-
ATTRIBUTE TLV is carried in PCRpt message in LSPA Object. The TLV
provides PCE with the 'configurable knobs' of this feature. In case
of PCE-Initiated LSP ([I-D.ietf-pce-pce-initiated-lsp]), this TLV is
included in the LSPA Object with PCInitiate message.
The format of the BANDWIDTH-USAGE-ATTRIBUTE TLV is shown in the The Overflow-Threshold-Percentage sub-TLV is used to decide if the
following figure: LSP bandwidth should be adjusted immediately.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=[TBD2] | Length | | Type=11 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | Percentage | Reserved | Count |
// sub-TLVs // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | Minimum-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
BANDWIDTH-USAGE-ATTRIBUTE TLV format Figure 14: Overflow-Threshold-Percentage Sub-TLV Format
Type: TBD2
Length: Variable
Value: This comprises one or more sub-TLVs.
Following sub-TLVs are defined in this document:
Type Len Name
-------------------------------------------------------------------
1 4 Bandwidth-Usage-Report-Interval sub-TLV
2 4 Bandwidth-Usage-Report-Threshold sub-TLV
3 4 Bandwidth-Usage-Report-Threshold-Percentage sub-TLV
4 4 Bandwidth-Usage-Report-Flow-Threshold sub-TLV
5 4 Bandwidth-Usage-Report-Flow-Threshold-Percentage sub-TLV
Future specification can define additional sub-TLVs. The Type is 11, the Length is 8 octets, and the value comprises the
following:
The presence of BANDWIDTH-USAGE-ATTRIBUTE TLV in LSPA Object means Percentage: The Overflow-Threshold value (7 bits), encoded in a
that the bandwidth usage reporting to PCE is enabled. All sub-TLVs percentage (an integer from 1 to 100). The value 0 is considered
are optional and any unrecognized sub-TLV MUST be silently ignored. to be invalid. If the percentage increase of the current MaxAvgBw
If a sub-TLV of same type appears more than once, only the first from the current bandwidth reservation is greater than or equal to
occurrence is processed and all others MUST be ignored. the threshold percentage, the overflow condition is met.
The BANDWIDTH-USAGE-ATTRIBUTE TLV can also be carried in PCUpd Reserved: MUST be set to zero on transmission and MUST be ignored on
message in LSPA Object in order to make updates to the attributes receipt.
such as Bandwidth-Usage-Report-Interval.
If sub-TLVs are not present, the default values based on the local Count: The Overflow-Count value (5 bits), encoded in an integer.
policy are assumed. The value 0 is considered to be invalid. The number of
consecutive samples for which the overflow condition MUST be met
for the LSP bandwidth is to be immediately adjusted to the current
bandwidth demand, bypassing the (up) Adjustment-Interval.
The following sub-sections describe the sub-TLVs which are currently Minimum-Threshold: The absolute Minimum-Threshold bandwidth value,
defined to be carried within the BANDWIDTH-USAGE-ATTRIBUTE TLV. encoded in IEEE floating point format (see [IEEE.754.1985]) and
expressed in bytes per second. The increase of the LSP bandwidth
MUST be at or above the Minimum-Threshold before the bandwidth
adjustment is made.
5.2.1. Bandwidth-Usage-Report-Interval sub-TLV In the case in which an invalid value is present, the sub-TLV MUST be
ignored and the previous value will be maintained.
The Bandwidth-Usage-Report-Interval sub-TLV specifies a time interval 5.2.5.3. Underflow-Threshold Sub-TLV
in seconds in which collected bandwidth samples should be reported to
PCE.
The Type is 1, Length is 4, and the value comprises of 4-octet time The Underflow-Threshold sub-TLV is used to decide if the LSP
interval, the valid range is from 1 to 604800, in seconds. Default bandwidth should be adjusted immediately.
value is 3600 seconds.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=1 | Length=4 | | Type=12 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth-Usage-Report-Interval | | Reserved | Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Underflow-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage-Report-Interval sub-TLV format Figure 15: Underflow-Threshold Sub-TLV Format
5.2.2. Bandwidth-Usage-Report-Threshold sub-TLV
The Bandwidth-Usage-Report-Threshold sub-TLV is used to decide when The Type is 12, the Length is 8 octets, and the value comprises the
the bandwidth samples collected so far should be reported following:
immediately, bypassing the report-interval.
0 1 2 3 Reserved: MUST be set to zero on transmission and MUST be ignored on
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 receipt.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=2 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth-Usage-Report Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage-Report-Threshold sub-TLV format Count: The Underflow-Count value (5 bits), encoded in an integer.
The value 0 is considered to be invalid. The number of
consecutive samples for which the underflow condition MUST be met
for the LSP bandwidth is to be immediately adjusted to the current
bandwidth demand, bypassing the Down-Adjustment-Interval.
The Type is 2, Length is 4, and the value comprises of - Underflow-Threshold: The absolute Underflow-Threshold bandwidth
value, encoded in IEEE floating point format (see [IEEE.754.1985])
and expressed in bytes per second. Refer to Section 3.1.2 of
[RFC3471] for a table of commonly used values. If the difference
between the current MaxAvgBw and the current bandwidth reservation
is greater than or equal to the threshold value, the underflow
condition is met.
o Threshold: The absolute threshold bandwidth value, encoded in IEEE In the case in which an invalid value is present, the sub-TLV MUST be
floating point format (see [IEEE.754.1985]), expressed in bytes ignored and the previous value will be maintained.
per second. Refer to Section 3.1.2 of [RFC3471] for a table of
commonly used values. If the increase or the decrease of at least
one of the bandwidth samples (BwSamples) collected so far compared
to the current bandwidth reservation is greater than or equal to
the threshold value, the bandwidth samples collected so far are
reported.
5.2.3. Bandwidth-Usage-Report-Threshold-Percentage sub-TLV 5.2.5.4. Underflow-Threshold-Percentage Sub-TLV
The Bandwidth-Usage-Report-Threshold-Percentage sub-TLV is used to The Underflow-Threshold-Percentage sub-TLV is used to decide if the
decide when the bandwidth samples collected so far should be reported LSP bandwidth should be adjusted immediately.
immediately, bypassing the report-interval.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=3 | Length=4 | | Type=13 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Percentage | | Percentage | Reserved | Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum-Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage-Report-Threshold-Percentage sub-TLV format Figure 16: Underflow-Threshold-Percentage Sub-TLV Format
The Type is 3, Length is 4, and the value comprises of - The Type is 13, the Length is 8 octets, and the value comprises the
following:
o Reserved: SHOULD be set to zero on transmission and MUST be Percentage: The Underflow-Threshold value (7 bits), encoded in
ignored on receipt. percentage (an integer from 1 to 100). The value 0 is considered
to be invalid. If the percentage decrease of the current MaxAvgBw
from the current bandwidth reservation is greater than or equal to
the threshold percentage, the underflow condition is met.
o Percentage: The threshold value, encoded in percentage (an integer Reserved: MUST be set to zero on transmission and MUST be ignored on
from 0 to 100). If the percentage increase or the decrease of at receipt.
least one of the bandwidth sample (BwSample) compared to the
current bandwidth reservation is greater than or equal to the
threshold percentage, the bandwidth samples collected so far are
reported.
5.2.4. Bandwidth-Usage-Report-Flow-Threshold sub-TLV Count: The Underflow-Count value (5 bits), encoded in an integer.
The value 0 is considered to be invalid. The number of
consecutive samples for which the underflow condition MUST be met
for the LSP bandwidth is to be immediately adjusted to the current
bandwidth demand, bypassing the Down-Adjustment-Interval.
The Bandwidth-Usage-Report-Flow-Threshold sub-TLV is used to decide Minimum-Threshold: The absolute Minimum-Threshold bandwidth value,
when the bandwidth samples collected should be reported immediately, encoded in IEEE floating point format (see [IEEE.754.1985]) and
bypassing the report-interval. expressed in bytes per second. The decrease of the LSP bandwidth
MUST be at or above the Minimum-Threshold before the bandwidth
adjustment is made.
0 1 2 3 In the case in which an invalid value is present, the sub-TLV MUST be
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 ignored and the previous value will be maintained.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=4 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth-Usage-Report-Flow Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage-Report-Flow-Threshold sub-TLV format 5.3. BANDWIDTH Object
The Type is 4, Length is 4, and the value comprises of - As per [RFC5440], the BANDWIDTH object (Object-Class value 5) is
defined with two Object-Type values as follows:
o Threshold: The absolute flow threshold bandwidth value, encoded in Requested Bandwidth: The BANDWIDTH Object-Type value is 1.
IEEE floating point format (see [IEEE.754.1985]), expressed in
bytes per second. Refer to Section 3.1.2 of [RFC3471] for a table
of commonly used values. If the increase or the decrease of the
current bandwidth sample (BwSample) compared to the current
bandwidth reservation is greater than or equal to the flow
threshold value, all the bandwidth samples collected so far are
reported immediately, bypassing the report-interval.
5.2.5. Bandwidth-Usage-Report-Flow-Threshold-Percent sub-TLV Reoptimization Bandwidth: The bandwidth of an existing TE LSP for
which a reoptimization is requested. The BANDWIDTH Object-Type
value is 2.
The Bandwidth-Usage-Report-Flow-Threshold-Percent sub-TLV is used to The PCC reports the calculated bandwidth to be adjusted (MaxAvgBw) to
decide when the bandwidth samples collected should be reported the stateful PCE using the existing 'Requested Bandwidth' with the
immediately, bypassing the report-interval. BANDWIDTH Object-Type as 1. The reporting of the 'reoptimization
bandwidth' with BANDWIDTH Object-Type as 2 is not required as the
stateful PCE is aware of the existing LSP bandwidth.
0 1 2 3 5.4. The PCInitiate Message
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=5 | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Percentage |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage-Report-Flow-Threshold-Percentage sub-TLV format A PCInitiate message is a PCEP message sent by a PCE to a PCC to
trigger LSP instantiation or deletion [RFC8281].
The Type is 5, Length is 4, and the value comprises of - For the PCE-initiated LSP with the auto-bandwidth feature enabled,
AUTO-BANDWIDTH-ATTRIBUTES TLV MUST be included in the LSPA object
with the PCInitiate message.
o Reserved: SHOULD be set to zero on transmission and MUST be The Routing Backus-Naur Form (RBNF) definition of the PCInitiate
ignored on receipt. message [RFC8281] is unchanged by this document.
o Percentage: The flow threshold value, encoded in percentage (an 5.5. The PCUpd Message
integer from 0 to 100). If the percentage increase or the
decrease of the current bandwidth sample (BwSample) compared to
the current bandwidth reservation is greater than or equal to the
threshold percentage, all the bandwidth samples collected so far
are reported immediately, bypassing the report-interval.
5.3. BANDWIDTH Object A PCUpd message is a PCEP message sent by a PCE to a PCC to update
the LSP parameters [RFC8231].
5.3.1. Auto-Bandwidth Adjusted Bandwidth For PCE-initiated LSPs with the auto-bandwidth feature enabled, the
AUTO-BANDWIDTH-ATTRIBUTES TLV MUST be included in the LSPA object
with the PCUpd message. The PCE can send this TLV to direct the PCC
to change the auto-bandwidth parameters.
As per [RFC5440], the BANDWIDTH object is defined with two The RBNF definition of the PCUpd message [RFC8231] is unchanged by
Object-Type values as following: this document.
o Requested Bandwidth: BANDWIDTH Object-Type value is 1. 5.6. The PCRpt Message
o Re-optimization Bandwidth: Bandwidth of an existing TE LSP for The PCRpt message [RFC8231] is a PCEP message sent by a PCC to a PCE
which a re-optimization is requested. BANDWIDTH Object-Type value to report the status of one or more LSPs.
is 2.
In the first model, where PCC calculates the adjusted bandwidth, PCC For PCE-initiated LSPs [RFC8281], the PCC creates the LSP using the
only reports the calculated bandwidth to be adjusted (MaxAvgBw) to attributes communicated by the PCE and the local values for the
the PCE. This is done via the existing 'Requested Bandwidth with unspecified parameters. After the successful instantiation of the
BANDWIDTH Object-Type as 1. LSP, the PCC automatically delegates the LSP to the PCE and generates
a PCRpt message to provide the status report for the LSP.
5.3.2. Bandwidth-Usage Report For both PCE-initiated and PCC-initiated LSPs, when the LSP is
delegated to a PCE for the very first time as well as after the
successful delegation, the BANDWIDTH object of type 1 is used to
specify the requested bandwidth in the PCRpt message.
A new BANDWIDTH object-type is defined to report the real-time The RBNF definition of the PCRpt message [RFC8231] is unchanged by
bandwidth usage of a TE LSP. this document.
The Object-type is [TBD3], the object length is variable with 5.7. The PCNtf Message
multiples of 4 bytes. The payload format is as follows:
0 1 2 3 As per [RFC5440], the PCEP Notification message (PCNtf) can be sent
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 by a PCEP speaker to notify its peer of a specific event.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BwSample1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BwSampleN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth-Usage format A PCEP speaker (PCE or PCC) SHOULD notify its PCEP peer (PCC or PCE)
when it is in an overwhelmed state due to the auto-bandwidth feature.
An implementation needs to make an attempt to send this notification
(when overwhelmed by auto-bandwidth adjustments) unless sending this
notification would only serve to increase the load further. Note
that when the notification is not received, the PCEP speaker would
continue to request bandwidth adjustments even when they cannot be
handled in a timely fashion.
o BwSample: The actual bandwidth usage, (the BwSample collected at Upon receipt of an auto-bandwidth overwhelm notification, the peer
the end of each sample-interval) encoded in IEEE floating point SHOULD NOT send any PCEP messages related to auto-bandwidth
format (see [IEEE.754.1985]), expressed in bytes per second. adjustment. If a PCEP message related to auto-bandwidth adjustment
is received while in an overwhelmed state, it MUST be ignored.
The Bandwidth-Usage object-type is used in the second deployment * When a PCEP speaker is overwhelmed, it SHOULD notify its peer by
model where PCC reports the TE LSP bandwidth usage and the PCE sending a PCNtf message with Notification-type = 5 (Auto-Bandwidth
decides the Auto-Bandwidth adjusted bandwidth. Overwhelm State) and Notification-value = 1 (Entering Auto-
Bandwidth Overwhelm State). Optionally, an OVERLOADED-DURATION
TLV [RFC5440] MAY be included to specify the time period during
which no further PCEP messages related to auto-bandwidth
adjustment should be sent.
The Bandwidth-Usage object-type can also be used for TE LSPs without * When the PCEP speaker is no longer in the overwhelm state and is
enabling the Auto-Bandwidth feature, to learn the actual bandwidth available to process the auto-bandwidth adjustments, it SHOULD
usage of the LSPs for other applications at the stateful PCE, details notify its peers by sending a PCNtf message with Notification-type
of which are beyond the scope of this document. = 5 (Auto-Bandwidth Overwhelm State) and Notification-value = 2
(Clearing Auto-Bandwidth Overwhelm State). A PCEP speaker SHOULD
send such notification to all peers if a Notification message
(Notification-type = 5, Notification-value = 1) was sent earlier.
This message is not sent if an OVERLOADED-DURATION TLV was
included and the PCEP speakers wishes for the peer to wait for the
expiration of that period of time before receiving further PCEP
messages related to auto-bandwidth adjustment.
5.4. The PCRpt Message When the auto-bandwidth feature is deployed, a PCE can send this
notification to a PCC when it reports frequent auto-bandwidth
adjustments. If a PCC is overwhelmed with resignaling, it can also
notify the PCE to not adjust the LSP bandwidth while in the overwhelm
state.
When LSP is delegated to a PCE for the very first time, BANDWIDTH Some dampening notification procedure (as per [RFC5440]) to avoid
object of type 1 is used to specify the requested bandwidth in the oscillations of the overwhelm state is RECOMMENDED. On receipt of an
PCRpt message. auto-bandwidth overwhelm notification from the PCE, a PCC should
consider the impact on the entire network. Moving the delegations of
auto-bandwidth-enabled LSPs to another PCE could cause further
overloading.
When the LSP is enabled with the Auto-Bandwidth feature, and 6. Manageability Considerations
BANDWIDTH-USAGE-ATTRIBUTE TLV is not present (Deployment model 1),
PCC SHOULD include the BANDWIDTH object of type 1 to specify the
calculated bandwidth to be adjusted to the PCE in the PCRpt message.
When the LSP is enabled with the Auto-Bandwidth feature, and 6.1. Control of Function and Policy
BANDWIDTH-USAGE-ATTRIBUTE TLV is present (Deployment model 2), PCC
SHOULD include the BANDWIDTH object of type [TBD] to report the
real-time bandwidth-usage to the PCE in the PCRpt message.
The definition of the PCRpt message (see [I-D.ietf-pce-stateful-pce]) The auto-bandwidth feature SHOULD be controlled on a per-LSP basis
is unchanged by this document. (at the PCC (head-end of the LSP) or PCE), and the values for auto-
bandwidth parameters, e.g., Sample-Interval, Adjustment-Interval (up/
down), Minimum-Bandwidth, Maximum-Bandwidth, and Adjustment-Threshold
(up/down), SHOULD be configurable by an operator.
5.5. The PCInitiate Message The Maximum-Bandwidth (and Minimum-Bandwidth) should be set to an
acceptable limit to avoid having an impact on the rest of the MPLS-TE
domain.
For PCE-initiated LSP [I-D.ietf-pce-pce-initiated-lsp] with Auto- The operator should make sure that the Overflow-Threshold is greater
Bandwidth feature enabled, AUTO-BANDWIDTH-ATTRIBUTE TLV MUST be than or at least equal to the Up-Adjustment-Threshold. And
included in LSPA object with the PCInitiate message. The rest of the similarly, it is important to ensure that the Underflow-Threshold is
processing remains unchanged. greater than or at least equal to the Down-Adjustment-Threshold.
6. Security Considerations 6.2. Information and Data Models
This document defines a new BANDWIDTH type, AUTO-BANDWIDTH-ATTRIBUTE A MIB module for gathering operational information about the PCEP is
TLV and BANDWIDTH-USAGE_ATTRIBUTE TLV which do not add any new defined in [RFC7420]. Additionally, the YANG module defined in
security concerns beyond those discussed in [RFC5440] and [PCE-PCEP-YANG] provides both configuration of PCEP as well as
[I-D.ietf-pce-stateful-pce]. operational management. These could be enhanced to provide controls
and indicators for support of the auto-bandwidth feature. Support
for various configuration knobs as well as counters of messages sent/
received containing the TLVs defined in this document could be added.
Some deployments may find the reporting of the real-time bandwidth- 6.3. Liveness Detection and Monitoring
usage information as extra sensitive and thus should employ suitable
PCEP security mechanisms like TCP-AO or [I-D.ietf-pce-pceps].
7. Manageability Considerations The mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already
listed in [RFC5440].
7.1. Control of Function and Policy 6.4. Verifying Correct Operations
The Auto-Bandwidth feature MUST BE controlled per tunnel (at ingress The mechanisms defined in this document do not imply any new
(PCC) or PCE), the values for parameters like sample-interval, operation verification requirements in addition to those already
adjustment-interval, minimum-bandwidth, maximum-bandwidth, listed in [RFC5440].
adjustment-threshold, report-interval, report-threshold SHOULD be
configurable by an operator.
7.2. Information and Data Models In the case in which an invalid value is present, the sub-TLV would
get ignored and the previous value will be maintained. In such a
case, the implementation SHOULD log the event.
[RFC7420] describes the PCEP MIB, there are no new MIB Objects 6.5. Requirements for Other Protocols
defined in this document.
7.3. Liveness Detection and Monitoring The mechanisms defined in this document do not add any new
requirements for other protocols.
Mechanisms defined in this document do not imply any new liveness 6.6. Impact on Network Operations
detection and monitoring requirements in addition to those already
listed in [RFC5440].
7.4. Verify Correct Operations In order to avoid any unacceptable impact on network operations, an
implementation SHOULD allow a limit to be placed on the number of
LSPs that can be enabled with the auto-bandwidth feature. For each
LSP enabled with the auto-bandwidth feature, there is an extra load
on the PCC, as it needs to monitor the traffic and report the
calculated bandwidth to be adjusted to the PCE. The PCE further
recomputes paths based on the requested bandwidth and updates the
path to the PCC, which, in turn, triggers the resignaling of the
path. All these steps add extra load and churn in the network; thus,
the operator needs to take due care while enabling these features on
a number of LSPs.
Mechanisms defined in this document do not imply any new operation An implementation MAY allow a limit to be placed on the rate of auto-
verification requirements in addition to those already listed in bandwidth-related messages sent by a PCEP speaker and received by a
[RFC5440]. peer. An implementation SHOULD also allow notifications to be sent
when a PCEP speaker is overwhelmed or when the rate of messages
reaches a threshold.
7.5. Requirements On Other Protocols Due care is required by the operator if a Sample-Interval value
significantly smaller than the default (5 minutes) is used, as small
Sample-Interval values, e.g., 1 minute or less, could cause
undesirable interactions with transport protocols. These undesirable
interactions result from providing insufficient time for transport
protocol reactions to a prior bandwidth adjustment to settle down
before Bandwidth-Samples are taken for the next bandwidth adjustment.
Mechanisms defined in this document do not add any new requirements 7. Security Considerations
on other protocols.
7.6. Impact On Network Operations This document defines AUTO-BANDWIDTH-CAPABILITY TLV and AUTO-
BANDWIDTH-ATTRIBUTES sub-TLVs, which do not add any substantial new
security concerns beyond those already discussed in [RFC8231] and
[RFC8281] for stateful PCE operations. As per [RFC8231], it is
RECOMMENDED that these PCEP extensions only be activated on
authenticated and encrypted sessions across PCEs and PCCs belonging
to the same administrative authority, using Transport Layer Security
(TLS) [RFC8253], as per the recommendations and best current
practices in BCP 195 [RFC7525] (unless explicitly set aside in
[RFC8253]).
Mechanisms defined in this document do not have any impact on network Incorrect auto-bandwidth parameters in the AUTO-BANDWIDTH-ATTRIBUTES
operations in addition to those already listed in [RFC5440]. sub-TLVs could have an adverse effect on the LSP as well as on the
network.
8. IANA Considerations 8. IANA Considerations
8.1. PCEP TLV Type Indicators 8.1. PCEP TLV Type Indicators
This document defines the following new PCEP TLVs; IANA is requested This document defines the following new PCEP TLVs; IANA has made the
to make the following allocations from this registry. following allocations from the "PCEP TLV Type Indicators" subregistry
http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type- of the "Path Computation Element Protocol (PCEP) Numbers" registry as
indicators follows:
Value Name Reference +-------+---------------------------+-----------+
TBD1 AUTO-BANDWIDTH-ATTRIBUTE [This I.D.] | Value | Description | Reference |
TBD2 BANDWIDTH-USAGE-ATTRIBUTE [This I.D.] +=======+===========================+===========+
| 36 | AUTO-BANDWIDTH-CAPABILITY | [RFC8733] |
+-------+---------------------------+-----------+
| 37 | AUTO-BANDWIDTH-ATTRIBUTES | [RFC8733] |
+-------+---------------------------+-----------+
8.2. AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV Table 3: PCEP TLV Type Indicators
This document specifies the AUTO-BANDWIDTH-ATTRIBUTE Sub-TLVs. IANA 8.2. AUTO-BANDWIDTH-CAPABILITY TLV Flag Field
is requested to create an "AUTO-BANDWIDTH-ATTRIBUTE Sub-TLV Types"
sub- registry in the "PCEP TLV Type Indicators" for the sub-TLVs
carried in the AUTO-BANDWIDTH-ATTRIBUTE TLV. This document defines
the following types:
Type Name Reference IANA has created a subregistry to manage the Flag field of the AUTO-
-------------------------------------------------------------- BANDWIDTH-CAPABILITY TLV within the "Path Computation Element
0 Reserved [This I.D.] Protocol (PCEP) Numbers" registry.
1 Sample-Interval sub-TLV [This I.D.]
2 Adjustment-Interval sub-TLV [This I.D.]
3 Adjustment-Threshold sub-TLV [This I.D.]
4 Adjustment-Threshold-Percentage sub-TLV [This I.D.]
5 Minimum-Bandwidth sub-TLV [This I.D.]
6 Maximum-Bandwidth sub-TLV [This I.D.]
7 Overflow-Threshold sub-TLV [This I.D.]
8 Overflow-Threshold-Percentage sub-TLV [This I.D.]
9 Underflow-Threshold sub-TLV [This I.D.]
10 Underflow-Threshold-Percentage sub-TLV [This I.D.]
11- Unassigned [This I.D.]
65535
8.3. BANDWIDTH-USAGE-ATTRIBUTE Sub-TLV New bit numbers are to be assigned by Standards Action [RFC8126].
Each bit should be tracked with the following qualities:
This document specifies the BANDWIDTH-USAGE-ATTRIBUTE Sub-TLVs. IANA * Bit number (counting from bit 0 as the most significant bit)
is requested to create an "BANDWIDTH-USAGE-ATTRIBUTE Sub-TLV Types"
sub-registry in the "PCEP TLV Type Indicators" for the sub-TLVs
carried in the BANDWIDTH-USAGE-ATTRIBUTE TLV. This document defines
the following types:
Type Name Reference * Capability description
--------------------------------------------------------------
0 Reserved [This I.D.]
1 Bandwidth-Usage-Report-Interval sub-TLV [This I.D.]
2 Bandwidth-Usage-Report-Threshold sub-TLV [This I.D.]
3 Bandwidth-Usage-Report-Threshold-Percentage [This I.D.]
sub-TLV
4 Bandwidth-Usage-Report-Flow-Threshold [This I.D.]
sub-TLV
5 Bandwidth-Usage-Report-Flow-Threshold [This I.D.]
-Percentage sub-TLV
6- Unassigned [This I.D.]
65535
8.4. BANDWIDTH Object * Defining RFC
This document defines new object type for the BANDWIDTH object; IANA The initial contents of the subregistry are empty, with all bits
is requested to make the following allocations from this registry. marked unassigned.
http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-objects
Object-Class Value Name Reference 8.3. AUTO-BANDWIDTH-ATTRIBUTES Sub-TLV
5 BANDWIDTH [This I.D.]
Object-Type This document specifies the AUTO-BANDWIDTH-ATTRIBUTES sub-TLVs. IANA
TBD3: Bandwidth-Usage Report has created an "AUTO-BANDWIDTH-ATTRIBUTES Sub-TLV Types" subregistry
within the "Path Computation Element Protocol (PCEP) Numbers"
registry to manage the type indicator space for sub-TLVs of the AUTO-
BANDWIDTH-ATTRIBUTES TLV. The valid range of values in the registry
is 0-65535. IANA has initialized the registry with the following
values. All other values in the registry should be marked as
"Unassigned".
IANA has set the Registration Procedure for this registry to read as
follows:
+-------------+------------------------+
| Range | Registration Procedure |
+=============+========================+
| 0-65503 | IETF Review |
+-------------+------------------------+
| 65504-65535 | Experimental Use |
+-------------+------------------------+
Table 4: Registration Procedure for
the "AUTO-BANDWIDTH-ATTRIBUTES Sub-
TLV" Registry
This document defines the following types:
+----------+--------------------------------------+-----------+
| Type | Name | Reference |
+==========+======================================+===========+
| 0 | Reserved | [RFC8733] |
+----------+--------------------------------------+-----------+
| 1 | Sample-Interval | [RFC8733] |
+----------+--------------------------------------+-----------+
| 2 | Adjustment-Interval | [RFC8733] |
+----------+--------------------------------------+-----------+
| 3 | Down-Adjustment-Interval | [RFC8733] |
+----------+--------------------------------------+-----------+
| 4 | Adjustment-Threshold | [RFC8733] |
+----------+--------------------------------------+-----------+
| 5 | Adjustment-Threshold-Percentage | [RFC8733] |
+----------+--------------------------------------+-----------+
| 6 | Down-Adjustment-Threshold | [RFC8733] |
+----------+--------------------------------------+-----------+
| 7 | Down-Adjustment-Threshold-Percentage | [RFC8733] |
+----------+--------------------------------------+-----------+
| 8 | Minimum-Bandwidth | [RFC8733] |
+----------+--------------------------------------+-----------+
| 9 | Maximum-Bandwidth | [RFC8733] |
+----------+--------------------------------------+-----------+
| 10 | Overflow-Threshold | [RFC8733] |
+----------+--------------------------------------+-----------+
| 11 | Overflow-Threshold-Percentage | [RFC8733] |
+----------+--------------------------------------+-----------+
| 12 | Underflow-Threshold | [RFC8733] |
+----------+--------------------------------------+-----------+
| 13 | Underflow-Threshold-Percentage | [RFC8733] |
+----------+--------------------------------------+-----------+
| 14-65503 | Unassigned | [RFC8733] |
+----------+--------------------------------------+-----------+
Table 5: Initial Contents of the "AUTO-BANDWIDTH-ATTRIBUTES
Sub-TLV" Registry
8.4. Error Object
This document defines a new Error-value for PCErr message of Error-
Type 19 (Invalid Operation) [RFC8231]. IANA has allocated a new
Error-value within the "PCEP-ERROR Object Error Types and Values"
subregistry of the "Path Computation Element Protocol (PCEP) Numbers"
registry as follows:
+------------+-----------+--------------------+-----------+
| Error-Type | Meaning | Error-value | Reference |
+============+===========+====================+===========+
| 19 | Invalid | 14: Auto-Bandwidth | [RFC8733] |
| | Operation | capability was not | |
| | | advertised | |
+------------+-----------+--------------------+-----------+
Table 6: Addition to the "PCEP-ERROR Object Error Types
and Values" Registry
8.5. Notification Object
IANA has allocated a new Notification-type and Notification-values
within the "Notification Object" subregistry of the "Path Computation
Element Protocol (PCEP) Numbers" registry as follows:
+-------------------+----------------+--------------------+---------+
| Notification-type | Name | Notification-value |Reference|
+===================+================+====================+=========+
| 5 | Auto-Bandwidth | 0: Unassigned |[RFC8733]|
| |Overwhelm State | | |
+-------------------+----------------+--------------------+---------+
| | | 1: Entering Auto- |[RFC8733]|
| | |Bandwidth Overwhelm | |
| | | State | |
+-------------------+----------------+--------------------+---------+
| | | 2: Clearing Auto- |[RFC8733]|
| | |Bandwidth Overwhelm | |
| | | State | |
+-------------------+----------------+--------------------+---------+
Table 7: Additions to the "Notification Object" Registry
9. References 9. References
9.1. Normative References 9.1. Normative References
[IEEE.754.1985]
IEEE, "Standard for Binary Floating-Point Arithmetic",
DOI 10.1109/IEEESTD.1985.82928, IEEE Standard 754, October
1985, <https://doi.org/10.1109/IEEESTD.1985.82928>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
(PCE) Communication Protocol (PCEP)", RFC 5440, March Element (PCE) Communication Protocol (PCEP)", RFC 5440,
2009. DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[I-D.ietf-pce-stateful-pce] [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
Crabbe, E., Minei, I., Medved, J., and R. Varga, "Recommendations for Secure Use of Transport Layer
"PCEP Extensions for Stateful PCE", Security (TLS) and Datagram Transport Layer Security
draft-ietf-pce-stateful-pce-11 (work in progress), (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
April 2015. 2015, <https://www.rfc-editor.org/info/rfc7525>.
[I-D.ietf-pce-pce-initiated-lsp] [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, Writing an IANA Considerations Section in RFCs", BCP 26,
"PCEP Extensions for PCE-initiated LSP Setup in a RFC 8126, DOI 10.17487/RFC8126, June 2017,
Stateful PCE Model", draft-ietf-pce-pce-initiated-lsp-04 <https://www.rfc-editor.org/info/rfc8126>.
(work in progress), April 2015.
[IEEE.754.1985] [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
Institute of Electrical and Electronics Engineers, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
"Standard for Binary Floating-Point Arithmetic", May 2017, <https://www.rfc-editor.org/info/rfc8174>.
IEEE Standard 754, August 1985.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<https://www.rfc-editor.org/info/rfc8231>.
[RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
"PCEPS: Usage of TLS to Provide a Secure Transport for the
Path Computation Element Communication Protocol (PCEP)",
RFC 8253, DOI 10.17487/RFC8253, October 2017,
<https://www.rfc-editor.org/info/rfc8253>.
[RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for PCE-Initiated LSP Setup in a Stateful PCE
Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
<https://www.rfc-editor.org/info/rfc8281>.
9.2. Informative References 9.2. Informative References
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching [PCE-PCEP-YANG]
(GMPLS) Signaling Functional Description", RFC 3471, Dhody, D., Hardwick, J., Beeram, V., and J. Tantsura, "A
January 2003. YANG Data Model for Path Computation Element
Communications Protocol (PCEP)", Work in Progress,
Internet-Draft, draft-ietf-pce-pcep-yang-13, 31 October
2019,
<https://tools.ietf.org/html/draft-ietf-pce-pcep-yang-13>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description",
RFC 3471, DOI 10.17487/RFC3471, January 2003,
<https://www.rfc-editor.org/info/rfc3471>.
[RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J. [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J.
Hardwick, "Path Computation Element Communication Protocol Hardwick, "Path Computation Element Communication Protocol
(PCEP) Management Information Base (MIB) Module", RFC (PCEP) Management Information Base (MIB) Module",
7420, December 2014. RFC 7420, DOI 10.17487/RFC7420, December 2014,
<https://www.rfc-editor.org/info/rfc7420>.
[I-D.ietf-pce-stateful-pce-app]
Zhang, X. and I. Minei, "Applicability of a Stateful Path
Computation Element (PCE)",
draft-ietf-pce-stateful-pce-app-04 (work in progress),
April 2015.
[I-D.ietf-pce-pceps] [RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a
Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure Stateful Path Computation Element (PCE)", RFC 8051,
Transport for PCEP", draft-ietf-pce-pceps-04 (work DOI 10.17487/RFC8051, January 2017,
in progress), May 2015. <https://www.rfc-editor.org/info/rfc8051>.
Acknowledgments Acknowledgments
Authors would like to thank Venugopal Reddy, Reeja Paul, Sandeep The authors would like to thank Robert Varga, Venugopal Reddy, Reeja
Boina and Avantika for their useful comments and suggestions. Paul, Sandeep Boina, Avantika, JP Vasseur, Himanshu Shah, Jonathan
Hardwick, and Adrian Farrel for their useful comments and
suggestions.
Contributors' Addresses Thanks to Daniel Franke, Joe Clarke, David Black, and Erik Kline for
the directorate reviews.
Thanks to Mirja Kühlewind, Barry Leiba, Benjamin Kaduk, and Roman
Danyliw for the IESG review.
Contributors
He Zekun He Zekun
Tencent Holdings Ltd, Tencent Holdings Ltd.
Shenzhen P.R.China Shenzhen
China
Email: kinghe@tencent.com Email: kinghe@tencent.com
Xian Zhang Xian Zhang
Huawei Technologies Huawei Technologies
Research Area F3-1B, Research Area F3-1B
Huawei Industrial Base, Huawei Industrial Base,
Shenzhen, 518129 Shenzhen
518129
China China
Phone: +86-755-28972645 Phone: +86-755-28972645
Email: zhang.xian@huawei.com Email: zhang.xian@huawei.com
Young Lee Young Lee
Huawei Technologies Samsung
1700 Alma Drive, Suite 100
Plano, TX 75075
USA
Phone: +1 972 509 5599 x2240 Email: younglee.tx@gmail.com
Fax: +1 469 229 5397
EMail: leeyoung@huawei.com
Authors' Addresses Authors' Addresses
Dhruv Dhody Dhruv Dhody (editor)
Huawei Technologies Huawei Technologies
Divyashree Techno Park, Whitefield Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560037 Bangalore 560066
Karnataka
India India
EMail: dhruv.ietf@gmail.com Email: dhruv.ietf@gmail.com
Udayasree Palle Rakesh Gandhi (editor)
Huawei Technologies Cisco Systems, Inc.
Divyashree Techno Park, Whitefield Canada
Bangalore, Karnataka 560037
India
EMail: udayasree.palle@huawei.com Email: rgandhi@cisco.com
Ravi Singh Udayasree Palle
Juniper Networks Individual Contributor
1194 N. Mathilda Ave.
Sunnyvale, CA 94089
USA
EMail: ravis@juniper.net Email: udayasreereddy@gmail.com
Rakesh Gandhi Ravi Singh
Cisco Systems, Inc. Individual Contributor
EMail: rgandhi@cisco.com Email: ravi.singh.ietf@gmail.com
Luyuan Fang Luyuan Fang
Microsoft Expedia Group, Inc.
15590 NE 31st St United States of America
Redmond, WA 98052
USA
EMail: lufang@microsoft.com Email: luyuanf@gmail.com
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