Networking Working Group Ran. Chen
Internet-Draft Zheng. Zhang
Intended status: Standards Track ZTE Corporation
Expires: May 2, 2016 October 30, 2015
BGP Link-State extensions for BIER
draft-chen-idr-bgp-ls-bier-ext-00
Abstract
Bit Index Explicit Replication (BIER) is an architecture that
provides optimal multicast forwarding through a "BIER domain" without
requiring intermediate routers to maintain any multicast related per-
flow state. BIER forwards and replicates packets based on a
BitString in the packet header.
This document specifies extensions to the BGP Link-state address-
family in order to advertising BIER information.
Status of This Memo
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This Internet-Draft will expire on May 2, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 2
3. BGP-LS Extensions for BIER . . . . . . . . . . . . . . . . . 3
3.1. The Link-State NLRI . . . . . . . . . . . . . . . . . . . 3
3.1.1. Node NLRI TLV . . . . . . . . . . . . . . . . . . . . 3
3.1.2. Link NLRI TLV . . . . . . . . . . . . . . . . . . . . 4
3.2. The new BGP-LS Attribute . . . . . . . . . . . . . . . . 5
3.2.1. BIER information sub-TLV . . . . . . . . . . . . . . 5
3.2.2. BIER-TE sub-TLV . . . . . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
4.1. BGP-LS node NLRI-Type . . . . . . . . . . . . . . . . . . 7
4.2. BGP-LS link NLRI-Type . . . . . . . . . . . . . . . . . . 7
4.3. BGP-LS Attribute TLV . . . . . . . . . . . . . . . . . . 7
4.3.1. BGP-LS node Attribute TLV . . . . . . . . . . . . . . 7
4.3.2. BGP-LS link Attribute TLV . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
7. Normative references . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
Bit Index Explicit Replication (BIER) is an architecture that
provides optimal multicast forwarding through a "BIER domain" without
requiring intermediate routers to maintain any multicast related per-
flow state. BIER forwards and replicates packets based on a
BitString in the packet header.
This document specifies extensions to the BGP Link-state address-
family in order to advertising BIER-specific. An external component
(e.g., a controller) then can collect BIER information in the
"northbound" direction across IGP areas or ASes and construct the
end-to-end path.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC2119.
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3. BGP-LS Extensions for BIER
BGP-LS [I-D.ietf-idr-ls-distribution] defines the BGP-LS NLRI that
can be a Node NLRI, a Link NLRI or a Prefix NLRI. The corresponding
BGP-LS attribute is a Node Attribute, a Link Attribute or a Prefix
Attribute.
In this document, we define two new "Node NLRI type" and a "link NLRI
type". The corresponding new BGP-LS attributes are also defined.
3.1. The Link-State NLRI
3.1.1. Node NLRI TLV
The following new "Node NLRI types" are defined for node Identifier
Information as following:
o IPV4 BFR-Prefix NLRI.
o IPV6 BFR-Prefix NLRI.
The following IPv4 BFR-Prefix NLRI is defined:
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
+-+-+-+-+-+-+-+-+
| Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPV4 BFR-Prefix |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1
The IPv6 BFR-Prefix NLRI is shown in the following figure:
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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
+-+-+-+-+-+-+-+-+
| Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPV6 BFR-Prefix |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2
3.1.2. Link NLRI TLV
The following new "link NLRI types" are defined for TE LSP Identifier
Information as following:
o IPV4 BIER-TE NLRI.
o IPV6 BIER-TE NLRI.
The IPV4 BIER-TE NLRI is shown in the following figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol-ID | Subdomain-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Node Descriptors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote Node Descriptors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3
Protocol-ID: TBD.
Subdomain-id: Unique value identifying the BIER sub-domain. 1 octet.
Local Node descriptors: The IPV4 BFR-Prefix of local node.4 octets.
Remote Node descriptors: The IPV4 BFR-Prefix of Remote node. 4
octets.
The IPV6 BIER-TE NLRI is shown in the following figure:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol-ID | Subdomain-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Local Node Descriptors |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Remote Node Descriptors |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4
Protocol-ID: TBD.
Subdomain-id: Unique value identifying the BIER sub-domain. 1 octet.
Local Node descriptors: The IPV6 BFR-Prefix of local node.16 octets.
Remote Node descriptors: The IPV6 BFR-Prefix of Remote node. 16
octets.
3.2. The new BGP-LS Attribute
3.2.1. BIER information sub-TLV
This sub-TLV SHOULD only be encoded in the BGP-LS node attributes
with a BFR Prefix NLRI that originates the corresponding BIER
information.
The following BIER info TLV is defined:
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 | subdomain-id | BSL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | BFR-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5
Type: TBD.
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Length: 1 octet.
Subdomain-id: Unique value identifying the BIER sub-domain, 1 octet.
BitString Length (BS Len): the number of bits in the BitString, 2
octets.
Reserved: reserved, must be 0 on transmission, ignored on reception.
May be used in future versions. 8 bits.
BFR-id: A 2 octets field encoding the BFR-id, as documented in
[I-D.ietf-bier-architecture].
3.2.2. BIER-TE sub-TLV
This TLV SHOULD only be encoded in the BGP-LS link attributes with a
BIER-TE NLRI that originates the corresponding BIER-TE information.
The following new Link Attribute TLV is defined:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-TLVs |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6
Type: TBD.
Length: variable.
Sub-TLVs:the following sub-sub-TLVs of the BIER-TE sub-TLV are
defined, the sub-sub-TLVs details as defined in [RFC3630]:
5- Traffic engineering metric(4 octets, as defined RFC3630 section
2.5.5).
6- Maximum bandwidth(4 octets, as defined RFC3630 section 2.5.6).
7- Maximum reservable bandwidth(4 octets, as defined RFC3630
section 2.5.7).
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8- Unreserved bandwidth(32 octets, as defined RFC3036 section
2.5.8).
4. IANA Considerations
This document requests assigning code-points from the registry for
BGP-LS NLRI-Types and BGP-LS attribute TLVs.
4.1. BGP-LS node NLRI-Type
IANA is requested to assign two new Node NLRI-Types:
+------+---------------------------+---------------+
| Type | NLRI Type | Reference |
+------+---------------------------+---------------+
| TBD | IPv4 BFR-Prefix NLRI | this document |
| TBD | IPv6 BFR-Prefix NLRI | this document |
+------+---------------------------+---------------+
4.2. BGP-LS link NLRI-Type
IANA is requested to assign two new link NLRI-Types:
+------+---------------------------+---------------+
| Type | NLRI Type | Reference |
+------+---------------------------+---------------+
| TBD | IPv4 BIER-TE NLRI | this document |
| TBD | IPv6 BIER-TE NLRI | this document |
+------+---------------------------+---------------+
4.3. BGP-LS Attribute TLV
4.3.1. BGP-LS node Attribute TLV
IANA is requested to assign new node Attribute TLV:
+-----------+---------------------+-----------------+
| TLV Code | Description | Value defined |
| Point | | in: |
+-----------+---------------------+-----------------+
| TBD | BIER Info | this document |
+-----------+---------------------+-----------------+
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4.3.2. BGP-LS link Attribute TLV
IANA is requested to assign new link Attribute TLV
+-----------+---------------------+-----------------+
| TLV Code | Description | Value defined |
| Point | | in: |
+-----------+---------------------+-----------------+
| TBD | BIER-TE TLV | this document |
+-----------+---------------------+-----------------+
5. Security Considerations
Procedures and protocol extensions defined in this document do not
affect the BGP security model. See [RFC6952] for details.
6. Acknowledgements
TBD.
7. Normative references
[I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit
Replication", draft-ietf-bier-architecture-02 (work in
progress), July 2015.
[I-D.ietf-idr-ls-distribution]
Gredler, H., Medved, J., Previdi, S., Farrel, A., and S.
Ray, "North-Bound Distribution of Link-State and TE
Information using BGP", draft-ietf-idr-ls-distribution-13
(work in progress), October 2015.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003,
<http://www.rfc-editor.org/info/rfc3630>.
[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,
<http://www.rfc-editor.org/info/rfc6952>.
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Authors' Addresses
Ran Chen
ZTE Corporation
No.50 Software Avenue,Yuhuatai District
Nanjing, Jiangsu Province 210012
China
Phone: +86 025 88014636
Email: chen.ran@zte.com.cn
Zheng Zhang
ZTE Corporation
No.50 Software Avenue,Yuhuatai District
Nanjing, Jiangsu Province 210012
China
Email: zhang.zheng@zte.com.cn
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