Network Working Group Yiqun Cai
Internet Draft Eric C. Rosen (Editor)
Intended Status: Proposed Standard IJsbrand Wijnands
Expires: August 1, 2010 Cisco Systems, Inc.
February 1, 2010
MVPN: S-PMSI Join Extensions and PIM/IPv6 over PIM/IPv4 Tunnels
draft-rosen-l3vpn-mvpn-spmsi-joins-00.txt
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Rosen, et al. [Page 1]
Internet Draft draft-rosen-l3vpn-mvpn-spmsi-joins-00.txt February 2010
described in the Simplified BSD License.
Abstract
"S-PMSI Join" messages are used in PIM-based MVPN procedures to bind
particular multicast flows to particular tunnels through a core
network. This document specifies extensions to the S-PMSI Join
mechanism that allow S-PMSI Join messages to specify IPv6 multicast
flows, that allow S-PMSI Join messages to specify MPLS tunnels, and
that allow a single UDP datagram to contain multiple S-PMSI Join
messages. It also specifies how to send PIM IPv6 control messages
over a PIM/IPv4 tunnel.
Table of Contents
1 Specification of requirements ......................... 3
2 Introduction .......................................... 3
3 S-PMSI Join Extensions ................................ 3
3.1 mLDP P2MP P-Tunnels ................................... 3
3.2 IPv6 (S,G) with GRE/IPv4 P-tunnels .................... 5
3.3 Encapsulation of S-PMSI Joins in UDP Datagrams ........ 6
4 PE-PE PIM/IPv6 over IPv4 P-Tunnel ..................... 6
5 IANA Considerations ................................... 6
6 Security Considerations ............................... 7
7 Acknowledgments ....................................... 7
8 Authors' Addresses .................................... 7
9 Normative References .................................. 8
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1. Specification of requirements
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].
2. Introduction
"S-PMSI Join" messages [MVPN] are used in PIM-based MVPN procedures
to bind particular multicast flows to particular tunnels through a
core network. This document specifies extensions to the S-PMSI Join
mechanism that are that allow S-PMSI Join messages to specify IPv6
multicast flows, that allow S-PMSI Join messages to specify MPLS
tunnels, that to allow a single UDP datagram to contain multiple
S-PMSI Join messages. This document also specifies how to send PIM
IPv6 control messages over a PIM/IPv4 tunnel.
This document uses terminology defined in [MVPN]: C-Source, C-Group,
C-flow, P-Group.
3. S-PMSI Join Extensions
The S-PMSI Join message is defined in section 7.4.2.2 of [MVPN]. In
this specification, we define the "type 2" and "type 3" S-PMSI Joins,
which are used when the S-PMSI tunnel is a P2MP LSP created by mLDP,
and the tunnel is to carry C-flows of, respectively, IPv4 or IPv6
multicast traffic.
The use of these messages with "wild card" addresses is specified in
[MVPN_WILD].
3.1. mLDP P2MP P-Tunnels
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-Source
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
| C-Group
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
| FEC Element
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
| Padding
+-+-+-+-+-+-+-+.......
Type (8 bits):
- 2 if C-Source and C-Group are IPv4 addresses,
- 3 if C-Source and C-Group are IPv6 addresses.
Length (16 bits): the total number of octets in the Type, Length,
Reserved and Value fields combined, rounded up to the next multiple
of 4, encoded as an unsigned binary integer.
Reserved (8 bits): This field SHOULD be zero when transmitted, and
MUST be ignored when received.
C-Source: address of the traffic source in the VPN
- for type 2, a 32-bit IPv4 address
- for type 3, a 128-bit IPv6 address
C-Group: address of the traffic destination in the VPN
- for type 2, a 32-bit IPv4 address
- for type 3, a 128-bit IPv6 address
FEC Element: this variable length field is a P2MP FEC element,
encoded as a TLV as specified in [MLDP].
Padding: 0-3 bytes, as needed for 32-bit alignment. The padding
bytes SHOULD be zero on transmission and MUST be ignored on
reception.
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3.2. IPv6 (S,G) with GRE/IPv4 P-tunnels
MVPN defines the S-PMSI Join type (type 1) used when assigning IPv4
(S,G) to a GRE/IPv4 P-tunnel. When assigning IPv6 (S,G) to a
GRE/IPv4 P-tunnel, S-PMSI Join type 4 is used, and the C-Source and
C-Group are IPv6 addresses. The P-Group address is an IPv4 address.
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| C-Source |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| C-Group |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| P-Group |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type (8 bits): 4
Length (16 bits): 40
Reserved (8 bits): This field SHOULD be zero when transmitted, and
MUST be ignored when received.
C-Source (128 bits):
the IPv6 address of the traffic source in the VPN.
C-Group (128 bits):
the IPv6 address of the multicast traffic destination address in
the VPN.
P-Group (32 bits):
the IPv4 group address that the PE router is going to use to
encapsulate the flow (C-Source, C-Group).
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3.3. Encapsulation of S-PMSI Joins in UDP Datagrams
All S-PMSI Joins are encapsulated in UDP datagrams.
If a UDP datagram contains a type 1 or type 2 S-PMSI Join, it MUST be
sent in an IPv4 datagram.
If a UDP datagram contains a type 3 or type 4 S-PMSI Join, it MUST be
sent in an IPv6 datagram. If an IPv4-based protocol is being used to
create the P-tunnels, then the IPv6 Source Address field of the UDP
datagram SHOULD be the IPv4-mapped IPv6 address [RFC4291] that
corresponds to the IPv4 address that the originating PE router uses
when participating in the protocol used to build the P-tunnels.
A single UDP datagram MAY carry multiple S-PMSI Join Messages, as
many as can fit entirely within it. If there are multiple S-PMSI
Joins in a UDP datagram, they MUST be of the same S-PMSI Join type.
The end of the last S-PMSI Join (as determined by the S-PMSI Join
length field) MUST coincide with the end of the UDP datagram, as
determined by the UDP length field. When processing a received UDP
datagram that contains one or more S-PMSI Joins, a router MUST be
able to process all the S-PMSI Joins that fit into the datagram.
4. PE-PE PIM/IPv6 over IPv4 P-Tunnel
If a VPN customer is using PIM over IPv6, but the SP is using an IPv4
infrastructure (i.e., is using an IPv4-based control protocol to
construct its P-tunnels), then the PE routers will need to originate
PIM control messages in IPv6 form, and send such messages through the
P-tunnels. The IPv6 Source Address field of any such IPv6 packet
SHOULD be the IPv4-mapped IPv6 address [RFC4291] that corresponds to
the IPv4 address that the originating PE router uses when
participating in the protocol used to build the P-tunnels. If the
IPv6 Destination Address field is the multicast address ALL-PIM-
ROUTERS, the IPv6 form of the address (ff02::d) is used.
5. IANA Considerations
[MVPN] creates an IANA registry for the "S-PMSI Join Message Type
Field". This document requires three new values:
- The value 2 should be registered, and its description should read
"mLDP P2MP S-PMSI for IPv4 traffic (unaggregated)".
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Internet Draft draft-rosen-l3vpn-mvpn-spmsi-joins-00.txt February 2010
- The value 3 should be registered, and its description should read
"mLDP P2MP S-PMSI for IPv6 traffic (unaggregated)".
- The value 4 should be registered, and its description should read
"GRE S-PMSI for IPv6 traffic (unaggregated)".
6. Security Considerations
There are no additional security considerations beyond those of
[MVPN].
7. Acknowledgments
The authors wish to thank DP Ayadevara, Arjen Boers, Rayen Mohanty,
Rajesh Sharma, and Karthik Subramanian.
8. Authors' Addresses
Yiqun Cai
Cisco Systems, Inc.
170 Tasman Drive
San Jose, CA, 95134
E-mail: ycai@cisco.com
Eric C. Rosen
Cisco Systems, Inc.
1414 Massachusetts Avenue
Boxborough, MA, 01719
E-mail: erosen@cisco.com
IJsbrand Wijnands
Cisco Systems, Inc.
De kleetlaan 6a Diegem 1831
Belgium
E-mail: ice@cisco.com
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9. Normative References
[MLDP] "Label Distribution Protocol Extensions for
Point-to-Multipoint and Multipoint-to-Multipoint Label Switched
Paths", Minei, Kompella, Wijnands, Thomas,
draft-ietf-mpls-ldp-p2mp-08.txt, October 2009
[MVPN] "Multicast in MPLS/BGP IP VPNs", Rosen, Aggarwal, et. al.,
draft-ietf-l3vpn-2547bis-mcast-10.txt, January 2010
[MVPN_WILD] "MVPN: S-PMSI Wild Card Selectors", Cai, Rosen, Wijnands,
draft-rosen-l3vpn-mvpn-wildcards-00.txt, February 2010
[RFC2119] "Key words for use in RFCs to Indicate Requirement
Levels.", Bradner, March 1997
[RFC4291] "IPv6 Addressing Architecture", Hinden, Deering, February
2006
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