LDP Downstream-on-Demand in Seamless MPLS
RFC 7032
Internet Engineering Task Force (IETF) T. Beckhaus, Ed.
Request for Comments: 7032 Deutsche Telekom AG
Category: Standards Track B. Decraene
ISSN: 2070-1721 Orange
K. Tiruveedhula
Juniper Networks
M. Konstantynowicz, Ed.
L. Martini
Cisco Systems, Inc.
October 2013
LDP Downstream-on-Demand in Seamless MPLS
Abstract
Seamless MPLS design enables a single IP/MPLS network to scale over
core, metro, and access parts of a large packet network
infrastructure using standardized IP/MPLS protocols. One of the key
goals of Seamless MPLS is to meet requirements specific to access
networks including high number of devices, device position in network
topology, and compute and memory constraints that limit the amount of
state access devices can hold. This can be achieved with LDP
Downstream-on-Demand (DoD) label advertisement. This document
describes LDP DoD use cases and lists required LDP DoD procedures in
the context of Seamless MPLS design.
In addition, a new optional TLV type in the LDP Label Request message
is defined for fast-up convergence.
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 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7032.
Beckhaus, et al. Standards Track [Page 1]
RFC 7032 LDP DoD October 2013
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Beckhaus, et al. Standards Track [Page 2]
RFC 7032 LDP DoD October 2013
Table of Contents
1. Introduction ....................................................4
2. Reference Topologies ............................................6
2.1. Access Topologies with Static Routing ......................6
2.2. Access Topologies with Access IGP .........................10
3. LDP DoD Use Cases ..............................................11
3.1. Initial Network Setup .....................................12
3.1.1. AN with Static Routing .............................12
3.1.2. AN with Access IGP .................................13
3.2. Service Provisioning and Activation .......................14
3.3. Service Changes and Decommissioning .......................16
3.4. Service Failure ...........................................17
3.5. Network Transport Failure .................................17
3.5.1. General Notes ......................................17
3.5.2. AN Failure .........................................18
3.5.3. AN/AGN Link Failure ................................19
3.5.4. AGN Failure ........................................20
3.5.5. AGN Network-Side Reachability Failure ..............20
4. LDP DoD Procedures .............................................20
4.1. LDP Label Distribution Control and Retention Modes ........21
4.2. LDP DoD Session Negotiation ...............................23
4.3. Label Request Procedures ..................................23
4.3.1. Access LSR/ABR Label Request .......................23
4.3.2. Label Request Retry ................................24
4.4. Label Withdraw ............................................25
4.5. Label Release .............................................26
Show full document text