draft-ietf-rtgwg-lfa-applicability-05.txt   draft-ietf-rtgwg-lfa-applicability-06.txt 
Network Working Group Clarence Filsfils Network Working Group Clarence Filsfils
Internet-Draft Cisco Systems Internet-Draft Cisco Systems
Intended status: Informational Pierre Francois Intended status: Informational Pierre Francois
Expires: July 14, 2012 Institute IMDEA Networks Expires: July 21, 2012 Institute IMDEA Networks
January 11, 2012 January 18, 2012
LFA applicability in SP networks LFA applicability in SP networks
draft-ietf-rtgwg-lfa-applicability-05 draft-ietf-rtgwg-lfa-applicability-06
Abstract Abstract
In this document, we analyze the applicability of -Loop-Free In this document, we analyze the applicability of the Loop-Free
Alternates in both core and access parts of Service Provider Alternates method of providing IP fast re-route in both the core and
networks. We provide design guides to favor their applicability the access parts of Service Provider networks. We consider both the
where relevant, typically in the access part of the network. link and node failure cases, and provide guidance on the
applicability of LFA to different network topologies, with special
emphasis on the access parts of the network.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 14, 2012. This Internet-Draft will expire on July 21, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 4, line 7 skipping to change at page 4, line 7
10. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 32 10. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 32
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 32 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 32
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33
13.1. Normative References . . . . . . . . . . . . . . . . . . . 33 13.1. Normative References . . . . . . . . . . . . . . . . . . . 33
13.2. Informative References . . . . . . . . . . . . . . . . . . 33 13.2. Informative References . . . . . . . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33
1. Introduction 1. Introduction
In this document, we analyze the applicability of Loop-Free In this document, we analyze the applicability of the Loop-Free
Alternates (LFA) [RFC5714] [RFC5286] in both core and access parts of Alternates (LFA) [RFC5714] [RFC5286] method of providing IP fast re-
Service Provider (SP) networks. We provide design guides to favor route (IPFRR) in both the core and the access parts of Service
their applicability where relevant, typically in the access part of Provider (SP) networks. We consider both the link and node failure
the network. cases, and provide guidance on the applicability of LFA to different
network topologies, with special emphasis on the access parts of the
network.
We first introduce the terminology used in this document in We first introduce the terminology used in this document in
Section 2. In Section 3, we describe typical access network designs Section 2. In Section 3, we describe typical access network designs
and we analyze them for LFA applicability. In Section 4, we describe and we analyze them for LFA applicability. In Section 4, we describe
a simulation framework for the study of LFA applicability in SP core a simulation framework for the study of LFA applicability in SP core
networks, and present results based on various SP networks. We then networks, and present results based on various SP networks. We then
emphasize the independence between protection schemes used in the emphasize the independence between protection schemes used in the
core and at the access level of the network. Finally we discuss the core and at the access level of the network. Finally we discuss the
key benefits of LFA which stem from its simplicity and we draw some key benefits of LFA which stem from its simplicity and we draw some
conclusions. conclusions.
skipping to change at page 23, line 31 skipping to change at page 23, line 31
to the applicability of LFAs for each destination, reached via any to the applicability of LFAs for each destination, reached via any
link of the topology. For node protection, we use "yes" to refer to link of the topology. For node protection, we use "yes" to refer to
the fact that node protection is achieved for a given node. the fact that node protection is achieved for a given node.
1. Intra Area Destinations 1. Intra Area Destinations
Link Protection Link Protection
+ Triangle: Full + Triangle: Full
+ Full-Mesh: Full + Full-Mesh: Full
+ Square: Full, except C1 has no LFA for dest A1 + Square: Full, except C1 has no LFA for dest A1
+ Extended U: Full + Extended U: Full
Node Protection Node Protection
+ Triangle: Full + Triangle: yes.
+ Full-Mesh: Full + Full-Mesh: yes.
+ Square: Full + Square: yes.
+ Extended U: Full + Extended U: yes.
2. Inter Area Destinations 2. Inter Area Destinations
Link Protection Link Protection
+ Triangle: Full + Triangle: Full
+ Full-Mesh: Full + Full-Mesh: Full
+ Square: Full + Square: Full
+ Extended U: Full + Extended U: Full
Node Protection Node Protection
+ Triangle: yes if e<c + Triangle: yes if e<c
+ Full-Mesh: yes for A failure, if e<c for C failure + Full-Mesh: yes for A failure, if e<c for C failure
+ Square: yes for A failure, if e<c for C failure + Square: yes for A failure, if e<c for C failure
skipping to change at page 33, line 29 skipping to change at page 33, line 29
We would like to thank Alvaro Retana and Stewart Bryant (in bold) for We would like to thank Alvaro Retana and Stewart Bryant (in bold) for
their precious comments on this work. their precious comments on this work.
13. References 13. References
13.1. Normative References 13.1. Normative References
[RFC5286] Atlas, A. and A. Zinin, "Basic Specification for IP Fast [RFC5286] Atlas, A. and A. Zinin, "Basic Specification for IP Fast
Reroute: Loop-Free Alternates", RFC 5286, September 2008. Reroute: Loop-Free Alternates", RFC 5286, September 2008.
13.2. Informative References
[RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework",
RFC 5714, January 2010.
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and [RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, December 1990. dual environments", RFC 1195, December 1990.
[RFC2328] Moy, J., "OSPF Version 2", RFC 2328, April 1998. [RFC2328] Moy, J., "OSPF Version 2", RFC 2328, April 1998.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, July 2008. for IPv6", RFC 5340, July 2008.
13.2. Informative References
[RFC5714] Shand, M. and S. Bryant, "IP Fast Reroute Framework",
RFC 5714, January 2010.
Authors' Addresses Authors' Addresses
Clarence Filsfils Clarence Filsfils
Cisco Systems Cisco Systems
Brussels 1000 Brussels 1000
BE BE
Email: cf@cisco.com Email: cf@cisco.com
Pierre Francois Pierre Francois
 End of changes. 8 change blocks. 
22 lines changed or deleted 26 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/