Network Working Group H. Chen
Internet-Draft M. McBride
Intended status: Standards Track Futurewei
Expires: October 16, 2021 A. Wang
China Telecom
G. Mishra
Verizon Inc.
Y. Fan
Casa Systems
L. Liu
Fujitsu
X. Liu
Volta Networks
April 14, 2021
OSPF Extensions for BIER-TE
draft-chen-bier-te-ospf-00
Abstract
This document describes OSPF extensions for distributing BitPositions
configured on the links in "Bit Index Explicit Replication Traffic
Engineering" (BIER-TE) domain.
Requirements Language
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] [RFC8174]
when, and only when, they appear in all capitals, as shown here.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 16, 2021.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Extensions to OSPFv2 . . . . . . . . . . . . . . . . . . . . 3
3. Security Considerations . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
[I-D.ietf-bier-te-arch] introduces Bit Index Explicit Replication
(BIER) Traffic/Tree Engineering (BIER-TE). It is an architecture for
per-packet stateless explicit point to multipoint (P2MP) multicast
path/tree. A link in a BIER-TE domain has its BitPositions. For a
link between two nodes X and Y, there are two BitPositions for two
forward connected adjacencies. These two adjacency BitPositions
could be configured on nodes X and Y respectively. The BitPosition
configured on X is the forward connected adjacency of Y. The
BitPosition configured on Y is the forward connected adjacency of X.
This document proposes OSPF extensions for distributing BitPositions
configured on the links in "Bit Index Explicit Replication Traffic
Engineering" (BIER-TE) domain.
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1.1. Terminology
BIER: Bit Index Explicit Replication.
BIER-TE: BIER Traffic Engineering.
BFR: Bit-Forwarding Router.
BFIR: Bit-Forwarding Ingress Router.
BFER: Bit-Forwarding Egress Router.
BFR-id: BFR Identifier. It is a number in the range [1,65535].
BFR-NBR: BFR Neighbor.
LSA: Link State Advertisement.
OSPF: Open Shortest Path First.
2. Extensions to OSPFv2
This section describes protocol extensions to OSPFv2 for distributing
BIER-TE information such as the BitPositions configured on the links
in a BIER-TE domain.
[RFC7684] defines the OSPFv2 Extended Link TLV to advertise the
information about a link. Multiple Link TLVs for the links of a
router are included in the OSPFv2 Extended Link Opaque LSA of the
router. The OSPFv2 Extended Link TLV has the following format:
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 (1) | Length (Variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: OSPFv2 Extended Link TLV
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Type: 1.
Length: Variable, dependent on Sub-TLVs.
Link Type, Link ID and Link Data: They are defined in Section A.4.2
of [RFC2328].
Reserved: SHOULD be set to 0 on transmission and MUST be ignored on
reception.
Under the OSPFv2 Extended Link TLV for a link, a Sub-TLV, called
BIER-TE Sub-TLV, is defined for distributing BIER-TE information
about the link. A BIER-TE Sub-TLV is included in the Link TLV for a
link of Link Type Point-to-Point or Broadcast (or say LAN or Transit
Network). The BIER-TE Sub-TLV has the following format:
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 (TBD1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-domain-id | MT-ID | BAR | IPA |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitPosition | DrEndBitPosition |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Sub-TLVs (variable) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: BIER-TE Sub-TLV
Type: TBD1 is to be assigned by IANA.
Length: Variable, dependent on Sub-Sub-TLVs.
sub-domain-id: Unique value identifying a BIER-TE sub-domain.
MT-ID: Multi-Topology ID identifying the topology that is associated
with the BIER-TE sub-domain.
BAR: Single-octet BIER Algorithm used to calculate underlay paths to
reach other BFRs. Values are allocated from the "BIER
Algorithm" registry defined in [RFC8401].
IPA: Single-octet IGP Algorithm used to either modify, enhance, or
replace the calculation of underlay paths to reach other BFRs
as defined by the BAR value. Values are defined in the "IGP
Algorithm Types" registry.
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BitPosition: A 2-octet field encoding the BitPosition locally
configured on the link/interface when the Link Type of the link
in the OSPFv2 Extended Link TLV containing this Sub-TLV is 1
(i.e., Point-to-Point connection to another router) or 2 (i.e.,
connection to Transit Network or say LAN).
DrEndBitPosition: A 2-octet field encoding the BitPosition of the
connection on the designated router (DR) end. This field is
valid when the Link Type in the OSPFv2 Extended Link TLV
containing this Sub-TLV is 2 (i.e., Transit Network or LAN).
For the other value of the Link Type, this field MUST be
ignored. The DrEndBitPosition may be configured on the link/
interface to a transit network (i.e., broadcast link or say
LAN).
No Sub-Sub-TLV is defined so far. Note that if each of BitPosition
and DrEndBitPosition uses more than 2 octets, we use 4 or more octets
for each of them.
3. Security Considerations
TBD.
4. IANA Considerations
Under "OSPFv2 Extended Link TLV Sub-TLV registry" as defined in
[RFC7684], IANA is requested to assign a new registry type for BIER-
TE Sub-TLV as follows:
+==============+===================+=====================+
| Sub-TLV Type | Sub-TLV Name | reference |
+==============+===================+=====================+
| TBD1 | BIER-TE | This document |
+--------------+-------------------+---------------------+
5. Acknowledgements
The authors would like to thank people for their comments to this
work.
6. References
6.1. Normative References
[I-D.ietf-bier-te-arch]
Eckert, T., Cauchie, G., and M. Menth, "Tree Engineering
for Bit Index Explicit Replication (BIER-TE)", draft-ietf-
bier-te-arch-09 (work in progress), October 2020.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>.
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <https://www.rfc-editor.org/info/rfc7684>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>.
[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
6.2. Informative References
[RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
OSPF Opaque LSA Option", RFC 5250, DOI 10.17487/RFC5250,
July 2008, <https://www.rfc-editor.org/info/rfc5250>.
[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
for Bit Index Explicit Replication (BIER) in MPLS and Non-
MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
2018, <https://www.rfc-editor.org/info/rfc8296>.
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[RFC8401] Ginsberg, L., Ed., Przygienda, T., Aldrin, S., and Z.
Zhang, "Bit Index Explicit Replication (BIER) Support via
IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018,
<https://www.rfc-editor.org/info/rfc8401>.
[RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A.,
Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2
Extensions for Bit Index Explicit Replication (BIER)",
RFC 8444, DOI 10.17487/RFC8444, November 2018,
<https://www.rfc-editor.org/info/rfc8444>.
[RFC8556] Rosen, E., Ed., Sivakumar, M., Przygienda, T., Aldrin, S.,
and A. Dolganow, "Multicast VPN Using Bit Index Explicit
Replication (BIER)", RFC 8556, DOI 10.17487/RFC8556, April
2019, <https://www.rfc-editor.org/info/rfc8556>.
Authors' Addresses
Huaimo Chen
Futurewei
Boston, MA
USA
Email: Huaimo.chen@futurewei.com
Mike McBride
Futurewei
Email: michael.mcbride@futurewei.com
Aijun Wang
China Telecom
Beiqijia Town, Changping District
Beijing, 102209
China
Email: wangaj3@chinatelecom.cn
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Gyan S. Mishra
Verizon Inc.
13101 Columbia Pike
Silver Spring MD 20904
USA
Phone: 301 502-1347
Email: gyan.s.mishra@verizon.com
Yanhe Fan
Casa Systems
USA
Email: yfan@casa-systems.com
Lei Liu
Fujitsu
USA
Email: liulei.kddi@gmail.com
Xufeng Liu
Volta Networks
McLean, VA
USA
Email: xufeng.liu.ietf@gmail.com
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