Networking Working Group L. Ginsberg, Ed.
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track S. Previdi
Expires: June 17, 2019 Q. Wu
Huawei
J. Tantsura
Apstra, Inc.
C. Filsfils
Cisco Systems, Inc.
December 14, 2018

BGP-LS Advertisement of IGP Traffic Engineering Performance Metric Extensions
draft-ietf-idr-te-pm-bgp-17

Abstract

This document defines new BGP-LS TLVs in order to carry the IGP Traffic Engineering Extensions defined in the IS-IS and OSPF protocols.

Status of This Memo

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Copyright Notice

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Table of Contents

1. Introduction

BGP-LS ([RFC7752]) defines NLRI and attributes in order to carry link-state information. New BGP-LS Link-Attribute TLVs are required in order to carry the Traffic Engineering Metric Extensions defined in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

2. Link Attribute TLVs for TE Metric Extensions

The following new Link Attribute TLVs are defined:

 TLV code-point                 Value
--------------------------------------------------------
 1114              Unidirectional Link Delay

 1115              Min/Max Unidirectional Link Delay

 1116              Unidirectional Delay Variation

 1117              Unidirectional Link Loss
 
 1118              Unidirectional Residual Bandwidth

 1119              Unidirectional Available Bandwidth

 1120              Unidirectional Bandwidth Utilization

[RFC7752].

2.1. Unidirectional Link Delay TLV

This TLV advertises the average link delay between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|  RESERVED   |                   Delay                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Figure 1

Type: 1114

Length: 4.

2.2. Min/Max Unidirectional Link Delay TLV

This sub-TLV advertises the minimum and maximum delay values between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED    |                   Min Delay                   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   RESERVED    |                   Max Delay                   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Figure 2

Type: 1115

Length: 8.

2.3. Unidirectional Delay Variation TLV

This sub-TLV advertises the average link delay variation between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  RESERVED     |               Delay Variation                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Figure 3

Type: 1116

Length: 4.

2.4. Unidirectional Link Loss TLV

This sub-TLV advertises the loss (as a packet percentage) between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|  RESERVED   |                  Link Loss                    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Type:1117

Length: 4.

2.5. Unidirectional Residual Bandwidth TLV

This sub-TLV advertises the residual bandwidth between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                          Residual Bandwidth                   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Type: 1118

Length: 4.

2.6. Unidirectional Available Bandwidth TLV

This sub-TLV advertises the available bandwidth between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Available Bandwidth                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Figure 4

Type: 1119

Length: 4.

2.7. Unidirectional Utilized Bandwidth TLV

This sub-TLV advertises the bandwidth utilization between two directly connected IGP link-state neighbors. The semantics of the value field in the TLV are described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Type                        |           Length              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Utilized Bandwidth                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

where:

Figure 5

Type: 1120

Length: 4.

2.8. Mappings to IGP Source sub-TLVs

This section documents the mappings between the Link Attribute TLVs defined in this document and the corresponding advertisements sourced by the IGPs.

For OSPFv2 and OSPFv3 the advertisements are defined in [RFC7471] . For IS-IS the advertisements are defined in [I-D.ietf-lsr-isis-rfc7810bis] .

   +---------------------------------------+----------+----------------+
   | Attribute Name                        |  IS-IS   | OSPFv2/OSPFv3  |
   |                                       | sub-TLV  |   sub-TLV      |
   +---------------------------------------+----------+----------------+
   | Unidirectional Link Delay             |   33     |     27         |
   +---------------------------------------+----------+----------------+
   | Min/Max Unidirectional Link Delay     |   34     |     28         |
   +---------------------------------------+----------+----------------+
   | Unidirectional Delay Variation        |   35     |     29         |
   +---------------------------------------+----------+----------------+
   | Unidirectional Link Loss              |   36     |     30         |
   +---------------------------------------+----------+----------------+
   | Unidirectional Residual Bandwidth     |   37     |     31         |
   +---------------------------------------+----------+----------------+
   | Unidirectional Available Bandwidth    |   38     |     32         |
   +---------------------------------------+----------+----------------+
   | Unidirectional Bandwidth Utilization  |   39     |     33         |
   +---------------------------------------+----------+----------------+


3. Security Considerations

Procedures and protocol extensions defined in this document do not affect the BGP security model. See the 'Security Considerations' section of [RFC4271] for a discussion of BGP security. Also refer to [RFC4272] and [RFC6952] for analysis of security issues for BGP. Security considerations for acquiring and distributing BGP-LS information are discussed in [RFC7752].

The TLVs introduced in this document are used to propagate IGP defined information ([I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471].) These TLVs represent the state and resource availability of the IGP link. The IGP instances originating these TLVs are assumed to support all the required security and authentication mechanisms (as described in [I-D.ietf-lsr-isis-rfc7810bis] and [RFC7471]) in order to prevent any security issue when propagating the TLVs into BGP-LS. The advertisement of the link attribute information defined in this document presents no additional risk beyond that associated with the existing set of link attribute information already supported in [RFC7752].

4. IANA Considerations

 TLV code-point                 Value
--------------------------------------------------------
 1114              Unidirectional Link Delay

 1115              Min/Max Unidirectional Link Delay

 1116              Unidirectional Delay Variation

 1117              Unidirectional Link Loss
 
 1118              Unidirectional Residual Bandwidth

 1119              Unidirectional Available Bandwidth

 1120              Unidirectional Bandwidth Utilization

IANA has made temporary assignments in the registry "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" for the new Link Attribute TLVs defined in the table below:

5. Contributors

The following people have substantially contributed to this document and should be considered co-authors:

Saikat Ray
Individual
Email: raysaikat@gmail.com

Hannes Gredler
RtBrick Inc.
Email: hannes@rtbrick.com

6. Acknowledgements

The authors wish to acknowledge comments from Ketan Talaulikar.

7. References

7.1. Normative References

[I-D.ietf-lsr-isis-rfc7810bis] Ginsberg, L., Previdi, S., Giacalone, S., Ward, D., Drake, J. and Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions", Internet-Draft draft-ietf-lsr-isis-rfc7810bis-03, November 2018.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A. and S. Previdi, "OSPF Traffic Engineering (TE) Metric Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015.
[RFC7752] Gredler, H., Medved, J., Previdi, S., Farrel, A. and S. Ray, "North-Bound Distribution of Link-State and Traffic Engineering (TE) Information Using BGP", RFC 7752, DOI 10.17487/RFC7752, March 2016.

7.2. Informative References

[RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006.
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", RFC 4272, DOI 10.17487/RFC4272, January 2006.
[RFC6952] Jethanandani, M., Patel, K. and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013.

Authors' Addresses

Les Ginsberg (editor) Cisco Systems, Inc. US EMail: ginsberg@cisco.com
Stefano Previdi Huawei IT EMail: stefano@previdi.net
Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu, 210012 China EMail: bill.wu@huawei.com
Jeff Tantsura Apstra, Inc. US EMail: jefftant.ietf@gmail.com
Clarence Filsfils Cisco Systems, Inc. Brussels, BE EMail: cfilsfil@cisco.com