PCE Communication Protocol (PCEP) Extensions for Label Switched Path (LSP) Scheduling with Stateful PCE
RFC 8934
Internet Engineering Task Force (IETF) H. Chen, Ed.
Request for Comments: 8934 Futurewei
Category: Standards Track Y. Zhuang, Ed.
ISSN: 2070-1721 Q. Wu
Huawei
D. Ceccarelli
Ericsson
October 2020
PCE Communication Protocol (PCEP) Extensions for Label Switched Path
(LSP) Scheduling with Stateful PCE
Abstract
This document defines a set of extensions to the stateful PCE
Communication Protocol (PCEP) to enable Label Switched Path (LSP)
path computation, activation, setup, and deletion based on scheduled
time intervals for the LSP and the actual network resource usage in a
centralized network environment, as stated in RFC 8413.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8934.
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Table of Contents
1. Introduction
2. Conventions Used in This Document
2.1. Terminology
3. Motivation and Objectives
4. Procedures and Mechanisms
4.1. LSP Scheduling Overview
4.2. Support of LSP Scheduling
4.2.1. LSP Scheduling
4.2.2. Periodical LSP Scheduling
4.3. Scheduled LSP Creation
4.4. Scheduled LSP Modifications
4.5. Scheduled LSP Activation and Deletion
5. PCEP Objects and TLVs
5.1. Stateful PCE Capability TLV
5.2. LSP Object
5.2.1. SCHED-LSP-ATTRIBUTE TLV
5.2.2. SCHED-PD-LSP-ATTRIBUTE TLV
6. The PCEP Messages
6.1. The PCRpt Message
6.2. The PCUpd Message
6.3. The PCInitiate Message
6.4. The PCReq message
6.5. The PCRep Message
6.6. The PCErr Message
7. Security Considerations
8. Manageability Consideration
8.1. Control of Function and Policy
8.2. Information and Data Models
8.3. Liveness Detection and Monitoring
8.4. Verify Correct Operations
8.5. Requirements on Other Protocols
8.6. Impact on Network Operations
9. IANA Considerations
9.1. PCEP TLV Type Indicators
9.1.1. SCHED-PD-LSP-ATTRIBUTE TLV Opt Field
9.1.2. Schedule TLVs Flag Field
9.2. STATEFUL-PCE-CAPABILITY TLV Flag Field
9.3. PCEP-ERROR Object Error Types and Values
10. References
10.1. Normative References
10.2. Informative References
Acknowledgments
Contributors
Authors' Addresses
1. Introduction
The PCE Communication Protocol (PCEP) defined in [RFC5440] is used
between a Path Computation Element (PCE) and a Path Computation
Client (PCC) (or other PCE) to enable path computation of
Multiprotocol Label Switching (MPLS) Traffic Engineering Label
Switched Paths (TE LSPs).
[RFC8231] describes a set of extensions to PCEP to provide stateful
control. A stateful PCE has access to not only the information
carried by the network's Interior Gateway Protocol (IGP) but also the
set of active paths and their reserved resources for its
computations. The additional state allows the PCE to compute
constrained paths while considering individual LSPs and their
interactions.
Traditionally, the usage and allocation of network resources,
especially bandwidth, can be supported by a Network Management System
(NMS) operation such as path pre-establishment. However, this does
not provide efficient usage of network resources. The established
paths reserve the resources forever, so they cannot be used by other
services even when they are not used for transporting any service.
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