draft-ietf-mpls-number-0-bw-te-lsps-11.txt   draft-ietf-mpls-number-0-bw-te-lsps-12.txt 
Networking Working Group JP. Vasseur, Ed. Networking Working Group JP. Vasseur, Ed.
Internet-Draft Cisco Systems, Inc Internet-Draft Cisco Systems, Inc
Intended status: Standards Track Matthew. R. Meyer Intended status: Standards Track Matthew. R. Meyer
Expires: February 19, 2009 Global Crossing Expires: March 5, 2009 Global Crossing
K. Kumaki K. Kumaki
KDDI Corporation KDDI Corporation
Alberto. Tempia Bonda Alberto. Tempia Bonda
Telecom Italia Telecom Italia
August 18, 2008 September 1, 2008
A Link-Type sub-TLV to convey the number of Traffic Engineering Label A Link-Type sub-TLV to convey the number of Traffic Engineering Label
Switched Paths signalled with zero reserved bandwidth across a link Switched Paths signalled with zero reserved bandwidth across a link
draft-ietf-mpls-number-0-bw-te-lsps-11 draft-ietf-mpls-number-0-bw-te-lsps-12
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 40 skipping to change at page 1, line 40
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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on February 19, 2009. This Internet-Draft will expire on March 5, 2009.
Abstract Abstract
Several Link-type sub-TLVs have been defined for OSPF and IS-IS in Several Link-type sub-Type-Lenght-Values (sub-TLVs) have been defined
the context of Multiprotocol Label Switching (MPLS) Traffic for Open Shortest Path First (OSPF) and Intermediate System to
Engineering (TE) in order to advertise some link characteristics such Intermediate System (IS-IS) in the context of Multiprotocol Label
as the available bandwidth, traffic engineering metric, Switching (MPLS) Traffic Engineering (TE) in order to advertise some
administrative group and so on. By making statistical assumption link characteristics such as the available bandwidth, traffic
about the aggregated traffic carried onto a set of TE Label Switched engineering metric, administrative group and so on. By making
Paths (LSPs) signalled with zero bandwith (referred to as statistical assumptions about the aggregated traffic carried onto a
unconstrained TE LSP in this document), and with the knowledge of the set of TE Label Switched Paths (LSPs) signalled with zero bandwith
number of unconstrained TE LSPs signalled across a link, algorithms (referred to as unconstrained TE LSP in this document), and with the
can be designed to load balance (existing or newly configured)
unconstrained TE LSP across a set of equal cost paths. This requires
knowledge of the number of unconstrained TE LSPs signalled across a knowledge of the number of unconstrained TE LSPs signalled across a
link. This document specifies a new Link-type Traffic Engineering link, algorithms can be designed to load balance (existing or newly
sub-TLV used to advertise the number of unconstrained TE LSP(s) configured) unconstrained TE LSP across a set of equal cost paths.
signalled across a link. This requires knowledge of the number of unconstrained TE LSPs
signalled across a link. This document specifies a new Link-type
Traffic Engineering sub-TLV used to advertise the number of
unconstrained TE LSP(s) signalled across a link.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Table of Contents Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Protocol extensions . . . . . . . . . . . . . . . . . . . . . . 4 3. Protocol extensions . . . . . . . . . . . . . . . . . . . . . 5
3.1. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Elements of procedure . . . . . . . . . . . . . . . . . . . . . 5 4. Elements of procedure . . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
Intellectual Property and Copyright Statements . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . . . 10
1. Terminology 1. Terminology
Terminology used in this document Terminology used in this document
CSPF: Constrained Shortest Path First CSPF: Constrained Shortest Path First
IGP : Interior Gateway Protocol IGP : Interior Gateway Protocol
LSA: Link State Advertisement LSA: Link State Advertisement
skipping to change at page 3, line 46 skipping to change at page 4, line 46
and/or node failures with pre-established backup tunnels. The and/or node failures with pre-established backup tunnels. The
traffic routed onto such unconstrained TE LSPs simply follows the IGP traffic routed onto such unconstrained TE LSPs simply follows the IGP
shortest path (since the TE LSP computed by the path computation shortest path (since the TE LSP computed by the path computation
algorithm (e.g. CSPF) will be no different than the IGP (Interior algorithm (e.g. CSPF) will be no different than the IGP (Interior
Gateway Protocol) shortest path should the TE metric be equal to the Gateway Protocol) shortest path should the TE metric be equal to the
IGP metric) but is protected with MPLS TE Fast Reroute. IGP metric) but is protected with MPLS TE Fast Reroute.
When a reoptimization process is triggered for an existing TE LSP, When a reoptimization process is triggered for an existing TE LSP,
the decision on whether to reroute that TE LSP onto a different path the decision on whether to reroute that TE LSP onto a different path
is governed by the discovery of a lower cost path satisfying the is governed by the discovery of a lower cost path satisfying the
constraints (other metric such that the percentage of reserved constraints (other metrics such that the percentage of reserved
bandwidth or the number of hops can also be used). Unfortunately, bandwidth or the number of hops can also be used). Unfortunately,
for instance in the presence of ECMPs (Equal Cost Multi-Paths) in metrics such as the path cost or the number of hops may be
symmetrical networks when unconstrained TE LSPs are used, such ineffective in various circumstances: for example, in the case of a
metrics (e.g. path cost, number of hops, ...) are usually ineffective symmetrical network with ECMPs (Equal Cost Multi-Paths), if the
and may lead to poorly load balanced traffic. network operator uses unconstrained TE LSP, this may lead to a poorly
load balanced traffic: indeed, several paths between a source and a
destination of a TE LSP may exist that have the same cost and the
reservable amount of bandwidth along each path cannot be used as a
tie-breaker.
By making statistical assumptions about the aggregated traffic By making statistical assumptions about the aggregated traffic
carried by a set of TE LSPs signalled with no bandwidth requirement carried by a set of TE LSPs signalled with no bandwidth requirement
(referred to as unconstrained TE LSPs in this document), algorithms (referred to as unconstrained TE LSPs in this document), algorithms
can be designed to load balance (existing or newly configured) can be designed to load balance (existing or newly configured)
unconstrained TE Label Switched Paths (LSPs) across a set of equal unconstrained TE Label Switched Paths (LSPs) across a set of equal
cost paths. This requires knowledge of the number of unconstrained cost paths. This requires knowledge of the number of unconstrained
Traffic Engineering Label Switched Paths (TE LSPs) signalled across Traffic Engineering Label Switched Paths (TE LSPs) signalled across
each link. each link.
Note that the specification of load balancing algorithms is outside Note that the specification of load balancing algorithms is outside
the scope of this document and is referred to for the sake of the scope of this document and is referred to for the sake of
illustration of the motivation for gathering such information. illustration of the motivation for gathering such information.
Furthermore, the knowledge of the number of unconstrained TE LSPs Furthermore, the knowledge of the number of unconstrained TE LSPs
signalled across each link can be used for other purposes (for signalled across each link can be used for other purposes, for
example to evaluate the number of affected unconstrained TE LSPs in example to evaluate the number of affected unconstrained TE LSPs in
case of a link failure). case of a link failure.
A set of Link-type sub-TLVs have been defined for OSPF and IS-IS (see A set of Link-type sub-TLVs have been defined for OSPF and IS-IS (see
[RFC3630] and [RFC3784]) in the context of MPLS Traffic Engineering [RFC3630] and [I-D.ietf-isis-te-bis]) in the context of MPLS Traffic
in order to advertise various link characteristics such as the Engineering in order to advertise various link characteristics such
available bandwidth, traffic engineering metric, administrative group as the available bandwidth, traffic engineering metric,
and so on. As currently defined in [RFC3630] and [RFC3784] the administrative group and so on. As currently defined in [RFC3630]
information related to the number of unconstrained TE LSP(s) is not and [I-D.ietf-isis-te-bis] the information related to the number of
available. This document specifies a new Link-type Traffic unconstrained TE LSP(s) is not available. This document specifies a
Engineering sub-TLV used to indicate the number of unconstrained TE new Link-type Traffic Engineering sub-TLV used to indicate the number
LSPs signalled across a link. of unconstrained TE LSPs signalled across a link.
Unconstrained TE LSPs that are configured and provisioned through a Unconstrained TE LSPs that are configured and provisioned through a
management system MAY be omitted from the count that is reported. management system MAY be omitted from the count that is reported.
3. Protocol extensions 3. Protocol extensions
Two Unconstrained TE LSP count sub-TLVs are defined that specify the Two Unconstrained TE LSP count sub-TLVs are defined that specify the
number of TE LSPs signalled with zero bandwidth across a link. number of TE LSPs signalled with zero bandwidth across a link.
3.1. IS-IS 3.1. IS-IS
The IS-IS Unconstrained TE LSP Count Sub-TLV is OPTIONAL and MUST NOT The IS-IS Unconstrained TE LSP Count Sub-TLV is OPTIONAL and MUST NOT
appear more than once within the extended IS reachability TLV (type appear more than once within the extended IS reachability TLV (type
22) specified in [RFC3784] or the MT Intermediate Systems TLV (type 22) specified in [I-D.ietf-isis-te-bis] or the MT Intermediate
222) specified in [RFC5120]. If a second instance of the Systems TLV (type 222) specified in [RFC5120]. If a second instance
Unconstrained TE LSP Count sub-TLV is present, the receiving system of the Unconstrained TE LSP Count sub-TLV is present, the receiving
MUST only process the first instance of the sub-TLV. system MUST only process the first instance of the sub-TLV.
The IS-IS Unconstrained TE LSP Count Sub-TLV format is defined below: The IS-IS Unconstrained TE LSP Count Sub-TLV format is defined below:
Type (1 octet): To be assigned by IANA (suggested value = 23) Type (1 octet): To be assigned by IANA (suggested value = 23)
Length (1 octet): 2 Length (1 octet): 2
Value (2 octets): number of unconstrained TE LSP(s) signalled across Value (2 octets): number of unconstrained TE LSP(s) signalled across
the link. the link.
skipping to change at page 5, line 33 skipping to change at page 6, line 37
Type (2 octets): To be assigned by IANA (suggested value = 23) Type (2 octets): To be assigned by IANA (suggested value = 23)
Length (2 octets): 4 Length (2 octets): 4
Value (4 octets): number of unconstrained TE LSP(s) signalled across Value (4 octets): number of unconstrained TE LSP(s) signalled across
the link. the link.
4. Elements of procedure 4. Elements of procedure
The absence of the Unconstrained TE LSP Count (sub-)TLV should be The absence of the Unconstrained TE LSP Count (sub-)TLV SHOULD be
interpreted as an absence of information about the link. interpreted as an absence of information about the link.
Similarly to other MPLS Traffic Engineering link characteristics, Similarly to other MPLS Traffic Engineering link characteristics,
LSA/LSP origination trigger mechanisms are outside the scope of this LSA/LSP origination trigger mechanisms are outside the scope of this
document. Care must be given to not trigger the systematic flooding document. Care must be given to not trigger the systematic flooding
of a new IS-IS LSP or OSPF LSA with a too high granularity in case of of a new IS-IS LSP or OSPF LSA with a too high granularity in case of
change of the number of unconstrained TE LSPs. change of the number of unconstrained TE LSPs.
5. IANA Considerations 5. IANA Considerations
skipping to change at page 6, line 22 skipping to change at page 7, line 23
the TE Link TLV. the TE Link TLV.
Suggested Value TLV Name Reference Suggested Value TLV Name Reference
23 Unconstrained TE LSP Count (sub-)TLV This document 23 Unconstrained TE LSP Count (sub-)TLV This document
6. Security Considerations 6. Security Considerations
The function described in this document does not create any new The function described in this document does not create any new
security issues for the OSPF and the IS-IS protocols. Security security issues for the OSPF and the IS-IS protocols. Security
considerations are covered in [RFC2328] and [RFC2470] for the base considerations are covered in [RFC2328] and [RFC5340] for the base
OSPF protocol and in [RFC1195] for IS-IS. OSPF protocol and in [RFC1195] and [I-D.ietf-isis-rfc3567bis] for
IS-IS.
A security framework for MPLS and Generalized MPLS can be found in
[I-D.ietf-mpls-mpls-and-gmpls-security-framework].
7. Acknowledgements 7. Acknowledgements
The authors would like to thank Jean-Louis Le Roux, Adrian Farrel, The authors would like to thank Jean-Louis Le Roux, Adrian Farrel,
Daniel King, Acee Lindem, Lou Berger, Attila Takacs and Loa Anderson Daniel King, Acee Lindem, Lou Berger, Attila Takacs, Pasi Eronen,
for their useful inputs. Russ Housley, Tim Folk and Loa Anderson for their useful inputs.
8. References 8. References
8.1. Normative References 8.1. Normative References
[I-D.ietf-isis-rfc3567bis]
Li, T. and R. Atkinson, "Intermediate System to
Intermediate System (IS-IS) Cryptographic
Authentication", draft-ietf-isis-rfc3567bis-03 (work in
progress), July 2008.
[I-D.ietf-isis-te-bis]
Li, T. and H. Smit, "IS-IS extensions for Traffic
Engineering", draft-ietf-isis-te-bis-00 (work in
progress), April 2008.
[I-D.ietf-ospf-ospfv3-traffic] [I-D.ietf-ospf-ospfv3-traffic]
Ishiguro, K., Manral, V., Davey, A., and A. Lindem, Ishiguro, K., Manral, V., Davey, A., and A. Lindem,
"Traffic Engineering Extensions to OSPF version 3", "Traffic Engineering Extensions to OSPF version 3",
draft-ietf-ospf-ospfv3-traffic-13 (work in progress), draft-ietf-ospf-ospfv3-traffic-13 (work in progress),
June 2008. June 2008.
[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.
[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, March 1997.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC2470] Crawford, M., Narten, T., and S. Thomas, "Transmission of
IPv6 Packets over Token Ring Networks", RFC 2470,
December 1998.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, (TE) Extensions to OSPF Version 2", RFC 3630,
September 2003. September 2003.
[RFC3784] Smit, H. and T. Li, "Intermediate System to Intermediate [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
System (IS-IS) Extensions for Traffic Engineering (TE)", for IPv6", RFC 5340, July 2008.
RFC 3784, June 2004.
8.2. Informative References 8.2. Informative References
[I-D.ietf-mpls-mpls-and-gmpls-security-framework]
Fang, L. and M. Behringer, "Security Framework for MPLS
and GMPLS Networks",
draft-ietf-mpls-mpls-and-gmpls-security-framework-03 (work
in progress), July 2008.
[RFC4090] Pan, P., Swallow, G., and A. Atlas, "Fast Reroute [RFC4090] Pan, P., Swallow, G., and A. Atlas, "Fast Reroute
Extensions to RSVP-TE for LSP Tunnels", RFC 4090, Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
May 2005. May 2005.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120, February 2008. Intermediate Systems (IS-ISs)", RFC 5120, February 2008.
Authors' Addresses Authors' Addresses
 End of changes. 20 change blocks. 
63 lines changed or deleted 84 lines changed or added

This html diff was produced by rfcdiff 1.35. The latest version is available from http://tools.ietf.org/tools/rfcdiff/