draft-ietf-mpls-rsvp-te-p2mp-05.txt   draft-ietf-mpls-rsvp-te-p2mp-06.txt 
Network Working Group R. Aggarwal (Editor) Network Working Group R. Aggarwal (Editor)
Internet Draft Juniper Networks Internet Draft Juniper Networks
Expiration Date: November 2006 Expiration Date: January 2007
D. Papadimitriou (Editor) D. Papadimitriou (Editor)
Alcatel Alcatel
S. Yasukawa (Editor) S. Yasukawa (Editor)
NTT NTT
Extensions to RSVP-TE for Point to Multipoint TE LSPs Extensions to RSVP-TE for Point-to-Multipoint TE LSPs
draft-ietf-mpls-rsvp-te-p2mp-05.txt draft-ietf-mpls-rsvp-te-p2mp-06.txt
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Abstract Abstract
This document describes extensions to Resource Reservation Protocol - This document describes extensions to Resource Reservation Protocol -
Traffic Engineering (RSVP-TE) for the setup of Traffic Engineered Traffic Engineering (RSVP-TE) for the setup of Traffic Engineered
(TE) point-to-multipoint (P2MP) Label Switched Paths (LSPs) in Multi- (TE) point-to-multipoint (P2MP) Label Switched Paths (LSPs) in Multi-
Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS)
networks. The solution relies on RSVP-TE without requiring a networks. The solution relies on RSVP-TE without requiring a
multicast routing protocol in the Service Provider core. Protocol multicast routing protocol in the Service Provider core. Protocol
elements and procedures for this solution are described. There can be elements and procedures for this solution are described.
various applications for P2MP TE LSPs such as IP multicast.
Specification of how such applications will use a P2MP TE LSP is There can be various applications for P2MP TE LSPs such as IP
outside the scope of this document. multicast. Specification of how such applications will use a P2MP TE
LSP is outside the scope of this document.
Table of Contents Table of Contents
1 Conventions used in this document ..................... 5 1 Conventions used in this document ..................... 5
2 Terminology ........................................... 5 2 Terminology ........................................... 5
3 Introduction .......................................... 5 3 Introduction .......................................... 5
4 Mechanism ............................................. 5 4 Mechanism ............................................. 6
4.1 P2MP Tunnels .......................................... 6 4.1 P2MP Tunnels .......................................... 6
4.2 P2MP LSP ............................................. 6 4.2 P2MP LSP ............................................. 6
4.3 Sub-Groups ............................................ 6 4.3 Sub-Groups ............................................ 7
4.4 S2L Sub-LSPs .......................................... 7 4.4 S2L Sub-LSPs .......................................... 7
4.4.1 Representation of a S2L Sub-LSP ....................... 7 4.4.1 Representation of an S2L Sub-LSP ...................... 7
4.4.2 S2L Sub-LSPs and Path Messages ........................ 7 4.4.2 S2L Sub-LSPs and Path Messages ........................ 8
4.5 Explicit Routing ...................................... 8 4.5 Explicit Routing ...................................... 8
5 Path Message .......................................... 10 5 Path Message .......................................... 11
5.1 Path Message Format ................................... 10 5.1 Path Message Format ................................... 11
5.2 Path Message Processing ............................... 11 5.2 Path Message Processing ............................... 12
5.2.1 Multiple Path Messages ................................ 12 5.2.1 Multiple Path Messages ................................ 12
5.2.2 Multiple S2L Sub-LSPs in one Path message ............. 13 5.2.2 Multiple S2L Sub-LSPs in one Path message ............. 13
5.2.3 Transit Fragmentation ................................. 15 5.2.3 Transit Fragmentation of Path State Information ....... 15
5.2.4 Control of Branch Fate Sharing ........................ 15 5.2.4 Control of Branch Fate Sharing ........................ 16
5.3 Grafting .............................................. 16 5.3 Grafting .............................................. 16
6 Resv Message .......................................... 16 6 Resv Message .......................................... 17
6.1 Resv Message Format ................................... 16 6.1 Resv Message Format ................................... 17
6.2 Resv Message Processing ............................... 18 6.2 Resv Message Processing ............................... 18
6.2.1 Resv Message Throttling ............................... 19 6.2.1 Resv Message Throttling ............................... 19
6.3 Record Routing ........................................ 19 6.3 Route Recording ....................................... 20
6.3.1 RRO Processing ........................................ 19 6.3.1 RRO Processing ........................................ 20
6.4 Reservation Style ..................................... 19 6.4 Reservation Style ..................................... 20
7 PathTear Message ...................................... 20 7 PathTear Message ...................................... 21
7.1 PathTear Message Format ............................... 20 7.1 PathTear Message Format ............................... 21
7.2 Pruning ............................................... 20 7.2 Pruning ............................................... 21
7.2.1 Implicit S2L Sub-LSP Teardown ......................... 20 7.2.1 Implicit S2L Sub-LSP Teardown ......................... 21
7.2.2 Explicit S2L Sub-LSP Teardown ........................ 21 7.2.2 Explicit S2L Sub-LSP Teardown ........................ 22
8 Notify and ResvConf Messages .......................... 21 8 Notify and ResvConf Messages .......................... 22
8.1 Notify Messages ....................................... 21 8.1 Notify Messages ....................................... 22
8.2 ResvConf Messages ..................................... 23 8.2 ResvConf Messages ..................................... 24
9 Refresh Reduction ..................................... 24 9 Refresh Reduction ..................................... 25
10 State Management ...................................... 24 10 State Management ...................................... 25
10.1 Incremental State Update .............................. 24 10.1 Incremental State Update .............................. 25
10.2 Combining Multiple Path Messages ...................... 25 10.2 Combining Multiple Path Messages ...................... 26
11 Error Processing ...................................... 26 11 Error Processing ...................................... 27
11.1 PathErr Messages ...................................... 26 11.1 PathErr Messages ...................................... 27
11.2 ResvErr Messages ...................................... 27 11.2 ResvErr Messages ...................................... 28
11.3 Branch Failure Handling ............................... 27 11.3 Branch Failure Handling ............................... 29
12 Admin Status Change ................................... 28 12 Admin Status Change ................................... 30
13 Label Allocation on LANs with Multiple Downstream Nodes ..28 13 Label Allocation on LANs with Multiple Downstream Nodes .30
14 P2MP LSP and Sub-LSP Re-optimization .................. 29 14 P2MP LSP and Sub-LSP Re-optimization .................. 30
14.1 Make-before-break ..................................... 29 14.1 Make-before-break ..................................... 30
14.2 Sub-Group Based Re-optimization ....................... 29 14.2 Sub-Group Based Re-optimization ....................... 31
15 Fast Reroute .......................................... 30 15 Fast Reroute .......................................... 31
15.1 Facility Backup ....................................... 30 15.1 Facility Backup ....................................... 32
15.1.1 Link Protection ....................................... 30 15.1.1 Link Protection ....................................... 32
15.1.2 Node Protection ....................................... 31 15.1.2 Node Protection ....................................... 32
15.2 One to One Backup ..................................... 31 15.2 one-to-one Backup ..................................... 33
16 Support for LSRs that are not P2MP Capable ............ 32 16 Support for LSRs that are not P2MP Capable ............ 34
17 Reduction in Control Plane Processing with LSP Hierarchy..34 17 Reduction in Control Plane Processing with LSP Hierarchy .36
18 P2MP LSP Remerging and Cross-Over ..................... 34 18 P2MP LSP Remerging and Cross-Over ..................... 36
18.1 Procedures ............................................ 35 18.1 Procedures ............................................ 37
18.1.1 Re-Merge Procedures ................................... 36 18.1.1 Re-Merge Procedures ................................... 38
19 New and Updated Message Objects ....................... 38 19 New and Updated Message Objects ....................... 40
19.1 SESSION Object ........................................ 38 19.1 SESSION Object ........................................ 40
19.1.1 P2MP LSP Tunnel IPv4 SESSION Object ................... 38 19.1.1 P2MP LSP Tunnel IPv4 SESSION Object ................... 40
19.1.2 P2MP LSP Tunnel IPv6 SESSION Object ................... 39 19.1.2 P2MP LSP Tunnel IPv6 SESSION Object ................... 41
19.2 SENDER_TEMPLATE object ................................ 39 19.2 SENDER_TEMPLATE object ................................ 41
19.2.1 P2MP LSP Tunnel IPv4 SENDER_TEMPLATE Object ........... 40 19.2.1 P2MP LSP Tunnel IPv4 SENDER_TEMPLATE Object ........... 42
19.2.2 P2MP LSP Tunnel IPv6 SENDER_TEMPLATE Object ........... 40 19.2.2 P2MP LSP Tunnel IPv6 SENDER_TEMPLATE Object ........... 42
19.3 <S2L_SUB_LSP> Object .................................. 41 19.3 S2L_SUB_LSP Object .................................... 43
19.3.1 <S2L_SUB_LSP> IPv4 Object ............................. 41 19.3.1 S2L_SUB_LSP IPv4 Object ............................... 44
19.3.2 <S2L_SUB_LSP> IPv6 Object ............................. 42 19.3.2 S2L_SUB_LSP IPv6 Object ............................... 44
19.4 FILTER_SPEC Object .................................... 42 19.4 FILTER_SPEC Object .................................... 44
19.4.1 P2MP LSP_IPv4 FILTER_SPEC Object ...................... 42 19.4.1 P2MP LSP_IPv4 FILTER_SPEC Object ...................... 44
19.4.2 P2MP LSP_IPv4 FILTER_SPEC Object ...................... 42 19.4.2 P2MP LSP_IPv6 FILTER_SPEC Object ...................... 45
19.5 P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO) ........... 43 19.5 P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO) ........... 45
19.6 P2MP SECONDARY_RECORD_ROUTE Object (SRRO) ............. 43 19.6 P2MP SECONDARY_RECORD_ROUTE Object (SRRO) ............. 45
20 IANA Considerations ................................... 43 20 IANA Considerations ................................... 45
20.1 New Class Numbers ..................................... 43 20.1 New Class Numbers ..................................... 45
20.2 New Class Types ....................................... 43 20.2 New Class Types ....................................... 46
20.3 New Error Values ...................................... 44 20.3 New Error Values ...................................... 46
20.4 LSP Attributes Flags .................................. 45 20.4 LSP Attributes Flags .................................. 47
21 Security Considerations ............................... 45 21 Security Considerations ............................... 47
22 Acknowledgements ...................................... 45 22 Acknowledgements ...................................... 48
23 Appendix .............................................. 45 23 References ............................................ 48
23.1 Example ............................................... 45 23.1 Normative References .................................. 48
24 References ............................................ 47 23.2 Informative References ................................ 49
24.1 Normative References .................................. 47 24 Appendix .............................................. 49
24.2 Informative References ................................ 48 24.1 Example ............................................... 50
25 Author Information .................................... 49 25 Author Information .................................... 51
25.1 Editor Information .................................... 49 25.1 Editor Information .................................... 51
25.2 Contributor Information ............................... 49 25.2 Contributor Information ............................... 52
26 Intellectual Property ................................. 52 26 Intellectual Property ................................. 54
27 Full Copyright Statement .............................. 52 27 Full Copyright Statement .............................. 54
28 Acknowledgement ....................................... 53 28 Acknowledgement ....................................... 55
1. Conventions used in this document 1. Conventions used in this document
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].
2. Terminology 2. Terminology
This document uses terminologies defined in [RFC3031], [RFC2205], This document uses terminologies defined in [RFC3031], [RFC2205],
[RFC3209], [RFC3473] and [RFC4461]. [RFC3209], [RFC3473], [RFC4461] and [RFC4090].
3. Introduction 3. Introduction
[RFC3209] defines a mechanism for setting up P2P TE LSPs in MPLS [RFC3209] defines a mechanism for setting up point-to-point (P2P)
networks. [RFC3473] defines extensions to [RFC3209] for setting up Traffic Engineered (TE) Label Switched Paths (LSPs) in Multi-Protocol
P2P TE LSPs in GMPLS networks. However these specifications do not Label Switching (MPLS) networks. [RFC3473] defines extensions to
provide a mechanism for building P2MP TE LSPs. [RFC3209] for setting up P2P TE LSPs in Generalized MPLS (GMPLS)
networks. However these specifications do not provide a mechanism
for building point-to-multipoint (P2MP) TE LSPs.
This document defines extensions to the RSVP-TE protocol [RFC3209], This document defines extensions to the RSVP-TE protocol [RFC3209],
[RFC3473] to support P2MP TE LSPs satisfying the set of requirements [RFC3473] to support P2MP TE LSPs satisfying the set of requirements
described in [RFC4461]. described in [RFC4461].
This document relies on the semantics of RSVP that RSVP-TE inherits This document relies on the semantics of the Resource Reservation
for building P2MP LSPs. A P2MP LSP is comprised of multiple S2L sub- Protocol (RSVP) that RSVP-TE inherits for building P2MP LSPs. A P2MP
LSPs. These S2L sub-LSPs are set up between the ingress and egress LSP is comprised of multiple source-to-leaf (S2L) sub-LSPs. These S2L
LSRs and are appropriately combined by the branch LSRs using RSVP sub-LSPs are set up between the ingress and egress-LSRs and are
semantics to result in a P2MP TE LSP. One Path message may signal one appropriately combined by the branch LSRs using RSVP semantics to
or multiple S2L sub-LSPs. Hence the S2L sub-LSPs belonging to a P2MP result in a P2MP TE LSP. One Path message may signal one or multiple
LSP can be signaled using one Path message or split across multiple S2L sub-LSPs for a single P2MP LSP. Hence the S2L sub-LSPs belonging
Path messages. to a P2MP LSP can be signaled using one Path message or split across
multiple Path messages.
Path computation and P2MP application specific aspects are outside There are various applications for P2MP TE LSPs and the signaling
the scope of this document. techniques described in this document can be used, sometimes in
combination with other techniques, to support different applications.
Specification of how applications will use P2MP TE LSPs and how the
paths of P2MP TE LSPs are computed is outside the scope of this
document.
4. Mechanism 4. Mechanism
This document describes a solution that optimizes data replication by This document describes a solution that optimizes data replication by
allowing non-ingress nodes in the network to be replication/branch allowing non-ingress nodes in the network to be replication/branch
nodes. A branch node is an LSR that is capable of replicating the nodes. A branch node is an LSR that replicates the incoming data on
incoming data on two or more outgoing interfaces. The solution relies to one or more outgoing interfaces. The solution relies on RSVP-TE in
on RSVP-TE in the network for setting up a P2MP TE LSP. the network for setting up a P2MP TE LSP.
The P2MP TE LSP is set up by associating multiple S2L sub-LSPs and The P2MP TE LSP is set up by associating multiple S2L sub-LSPs and
relying on data replication at branch nodes. This is described relying on data replication at branch nodes. This is described
further in the following sub-sections by describing P2MP Tunnels and further in the following sub-sections by describing P2MP Tunnels and
how they relate to S2L sub-LSPs. how they relate to S2L sub-LSPs.
4.1. P2MP Tunnels 4.1. P2MP Tunnels
The specific aspect related to a P2MP TE LSP is the action required The defining feature of a P2MP TE LSP is the action required at
at a branch node, where data replication occurs. Incoming MPLS branch nodes where data replication occurs. Incoming MPLS labeled
labeled data is appropriately replicated to several outgoing data is replicated to outgoing interfaces which may use different
interfaces which may have different labels. labels for the data.
A P2MP TE Tunnel comprises one or more P2MP LSPs. A P2MP TE Tunnel is A P2MP TE Tunnel comprises one or more P2MP LSPs. A P2MP TE Tunnel is
identified by a P2MP SESSION object. This object contains the identified by a P2MP SESSION object. This object contains the
identifier of the P2MP Session which includes the P2MP ID, a tunnel identifier of the P2MP Session which includes the P2MP Identifier
ID and an extended tunnel ID. (P2MP ID), a tunnel Identifier (Tunnel ID) and an extended tunnel
identifier (Extended Tunnel ID). The P2MP ID is a four octet number
and is unique within the scope of the ingress LSR.
The fields of a P2MP SESSION object are identical to those of the The <P2MP ID, Tunnel ID, Extended Tunnel ID> tuple provides an
SESSION object defined in [RFC3209] except that the Tunnel Endpoint identifier for the set of destinations of the P2MP TE Tunnel.
Address field is replaced by the P2MP Identifier (P2MP ID) field.
The P2MP ID provides an identifier for the set of destinations of the The fields of the P2MP SESSION object are identical to those of the
P2MP TE Tunnel. SESSION object defined in [RFC3209] except that the Tunnel Endpoint
Address field is replaced by the P2MP ID field. The P2MP SESSION
object is defined in section 19.1
4.2. P2MP LSP 4.2. P2MP LSP
A P2MP LSP is identified by the combination of the P2MP ID, Tunnel A P2MP LSP is identified by the combination of the P2MP ID, Tunnel ID
ID, and Extended Tunnel ID that are part of the P2MP SESSION object, and Extended Tunnel ID that are part of the P2MP SESSION object, and
and the tunnel sender address and LSP ID fields of the P2MP the tunnel sender address and LSP ID fields of the P2MP
SENDER_TEMPLATE object. The new P2MP SENDER_TEMPLATE object is SENDER_TEMPLATE object. The new P2MP SENDER_TEMPLATE object is
defined in section 20.2. defined in section 19.2.
4.3. Sub-Groups 4.3. Sub-Groups
As with all other RSVP controlled LSPs, P2MP LSP state is managed As with all other RSVP controlled LSPs, P2MP LSP state is managed
using RSVP messages. While use of RSVP messages is the same, P2MP LSP using RSVP messages. While the use of RSVP messages is the same, P2MP
state differs from P2P LSP state in a number of ways. The two most LSP state differs from P2P LSP state in a number of ways. A P2MP LSP
notable differences are that a P2MP LSP comprises multiple S2L Sub- comprises multiple S2L Sub-LSPs and as a result of this it may not be
LSPs and that, as a result of this, it may not be possible to possible to represent full state in a single IP packet. It must also
represent full state in a single IP packet and even more likely that be possible to efficiently add and remove endpoints to and from P2MP
it can't fit into a single IP packet. It must also be possible to TE LSPs. An additional issue is that the P2MP LSP must also handle
efficiently add and remove endpoints to and from P2MP TE LSPs. An the state "remerge" problem, see [RFC4461] and section 18.
additional issue is that the P2MP LSP must also handle the state
"remerge" problem, see [RFC4461].
These differences in P2MP state are addressed through the addition of These differences in P2MP state are addressed through the addition of
a sub-group identifier (Sub-Group ID) and sub-group originator (Sub- a sub-group identifier (Sub-Group ID) and sub-group originator (Sub-
Group Originator ID) to the SENDER_TEMPLATE and FILTER_SPEC objects. Group Originator ID) to the SENDER_TEMPLATE and FILTER_SPEC objects.
Taken together the Sub-Group ID and Sub-Group Originator ID are Taken together the Sub-Group ID and Sub-Group Originator ID are
referred to as the Sub-Group fields. referred to as the Sub-Group fields.
The Sub-Group fields, together with rest of the SENDER_TEMPLATE and The Sub-Group fields, together with rest of the SENDER_TEMPLATE and
SESSION objects, are used to represent a portion of a P2MP LSP's SESSION objects, are used to represent a portion of a P2MP LSP's
state. This portion of a P2MP LSP's state refers only to signaling state. This portion of a P2MP LSP's state refers only to signaling
state and not data plane replication or branching. For example, it is state and not data plane replication or branching. For example, it is
possible for a node to "branch" signaling state for a P2MP LSP, but possible for a node to "branch" signaling state for a P2MP LSP, but
to not branch the data associated with the P2MP LSP. Typical to not branch the data associated with the P2MP LSP. Typical
applications for generation and use of multiple subgroups are adding applications for generation and use of multiple sub-groups are adding
an egress and semantic fragmentation to ensure that a Path message an egress, and semantic fragmentation to ensure that a Path message
remains within a single IP packet. remains within a single IP packet.
4.4. S2L Sub-LSPs 4.4. S2L Sub-LSPs
A P2MP LSP is constituted of one or more S2L sub-LSPs. A P2MP LSP is constituted of one or more S2L sub-LSPs.
4.4.1. Representation of a S2L Sub-LSP 4.4.1. Representation of an S2L Sub-LSP
An S2L sub-LSP exists within the context of a P2MP LSP. Thus it is An S2L sub-LSP exists within the context of a P2MP LSP. Thus it is
identified by the P2MP ID, Tunnel ID, and Extended Tunnel ID that are identified by the P2MP ID, Tunnel ID, and Extended Tunnel ID that are
part of the P2MP SESSION, the tunnel sender address and LSP ID fields part of the P2MP SESSION, the tunnel sender address and LSP ID fields
of the P2MP SENDER_TEMPLATE object, and the S2L sub-LSP destination of the P2MP SENDER_TEMPLATE object, and the S2L sub-LSP destination
address that is part of the <S2L_SUB_LSP> object. The <S2L_SUB_LSP> address that is part of the S2L_SUB_LSP object. The S2L_SUB_LSP
object is defined in section 20.3. object is defined in section 19.3.
An EXPLICIT_ROUTE Object (ERO) or P2MP SECONDARY_EXPLICIT_ROUTE An EXPLICIT_ROUTE Object (ERO) or P2MP_SECONDARY_EXPLICIT_ROUTE
Object (SERO) is used to optionally specify the explicit route of a Object (SERO) is used to optionally specify the explicit route of a
S2L sub-LSP. Each ERO or SERO that is signaled corresponds to a S2L sub-LSP. Each ERO or SERO that is signaled corresponds to a
particular <S2L_SUB_LSP> object. Details of explicit route encoding particular S2L_SUB_LSP object. Details of explicit route encoding
are specified in section 4.5. The SECONDARY_EXPLICIT_ROUTE Object is are specified in section 4.5. The SECONDARY_EXPLICIT_ROUTE Object is
defined in [RECOVERY], a new P2MP SECONDARY_EXPLICIT_ROUTE Object C- defined in [RECOVERY], a new P2MP SECONDARY_EXPLICIT_ROUTE Object C-
type is defined in Section 20.5 and a matching P2MP type is defined in Section 19.5 and a matching
SECONDARY_RECORD_ROUTE Object C-type is defined in Section 20.6. P2MP_SECONDARY_RECORD_ROUTE Object C-type is defined in Section 19.6.
4.4.2. S2L Sub-LSPs and Path Messages 4.4.2. S2L Sub-LSPs and Path Messages
The mechanism in this document allows a P2MP LSP to be signaled using The mechanism in this document allows a P2MP LSP to be signaled using
one or more Path messages. Each Path message may signal one or more one or more Path messages. Each Path message may signal one or more
S2L sub-LSPs. Support for multiple Path messages is desirable as one S2L sub-LSPs. Support for multiple Path messages is desirable as one
Path message may not be large enough to contain all the S2L sub-LSPs; Path message may not be large enough to contain all the S2L sub-LSPs;
and they also allow separate manipulation of sub-trees of the P2MP and they also allow separate manipulation of sub-trees of the P2MP
LSP. The reason for allowing a single Path message, to signal LSP. The reason for allowing a single Path message, to signal
multiple S2L sub-LSPs, is to optimize the number of control messages multiple S2L sub-LSPs, is to optimize the number of control messages
needed to setup a P2MP LSP. needed to setup a P2MP LSP.
4.5. Explicit Routing 4.5. Explicit Routing
When a Path message signals a single S2L sub-LSP (that is, the Path When a Path message signals a single S2L sub-LSP (that is, the Path
message is only targeting a single leaf in the P2MP tree), the message is only targeting a single leaf in the P2MP tree), the
EXPLICIT_ROUTE object encodes the path from the ingress LSR to the EXPLICIT_ROUTE object encodes the path to the egress-LSR. The Path
egress LSR. The Path message also includes the <S2L_SUB_LSP> object message also includes the S2L_SUB_LSP object for the S2L sub-LSP
for the S2L sub-LSP being signaled. The < [<EXPLICIT_ROUTE>], being signaled. The < [<EXPLICIT_ROUTE>], <S2L_SUB_LSP> > tuple
<S2L_SUB_LSP> > tuple represents the S2L sub-LSP and is referred to represents the S2L sub-LSP and is referred to as the sub-LSP
as the sub-LSP descriptor. The absence of the ERO should be descriptor. The absence of the ERO should be interpreted as
interpreted as requiring hop-by-hop routing for the sub-LSP based on requiring hop-by-hop routing for the sub-LSP based on the S2L sub-LSP
the S2L sub-LSP destination address field of the <S2L_SUB_LSP> destination address field of the S2L_SUB_LSP object.
object.
When a Path message signals multiple S2L sub-LSPs the path of the When a Path message signals multiple S2L sub-LSPs the path of the
first S2L sub-LSP, from the ingress LSR to the egress LSR, is encoded first S2L sub-LSP, to the egress-LSR, is encoded in the ERO. The
in the ERO. The first S2L sub-LSP is the one that corresponds to the first S2L sub-LSP is the one that corresponds to the first
first <S2L_SUB_LSP> object in the Path message. The S2L sub-LSPs S2L_SUB_LSP object in the Path message. The S2L sub-LSPs
corresponding to the <S2L_SUB_LSP> objects that follow are termed as corresponding to the S2L_SUB_LSP objects that follow are termed as
subsequent S2L sub-LSPs. subsequent S2L sub-LSPs.
The path of each subsequent S2L sub-LSP is encoded in a P2MP The path of each subsequent S2L sub-LSP is encoded in a
SECONDARY_EXPLICIT_ROUTE object (SERO). The format of the SERO is the P2MP_SECONDARY_EXPLICIT_ROUTE object (SERO). The format of the SERO
same as an ERO (as defined in [RFC3209]). Each subsequent S2L sub-LSP is the same as an ERO (as defined in [RFC3209] and [RFC3473]). Each
is represented by tuples of the form < [<P2MP subsequent S2L sub-LSP is represented by tuples of the form < [<P2MP
SECONDARY_EXPLICIT_ROUTE>] <S2L_SUB_LSP> >. An SERO for a particular SECONDARY_EXPLICIT_ROUTE>] <S2L_SUB_LSP> >. An SERO for a particular
S2L sub-LSP includes only the path from a certain branch LSR to the S2L sub-LSP includes only the path from a branch LSR to the egress-
egress LSR if the path to that branch LSR can be derived from the ERO LSR of that S2L sub-LSP. The branch MUST appear as an explicit hop
or other SEROs. The absence of an SERO should be interpreted as in the ERO or some other SERO. The absence of an SERO should be
requiring hop-by-hop routing for that S2L sub-LSP. Note that the interpreted as requiring hop-by-hop routing for that S2L sub-LSP.
destination address is carried in the S2L sub-LSP object. The Note that the destination address is carried in the S2L sub-LSP
encoding of the SERO and <S2L_SUB_LSP> object are described in detail object. The encoding of the SERO and S2L_SUB_LSP object are described
in section 20. in detail in section 19.
In order to avoid the potential repetition of path information for In order to avoid the potential repetition of path information for
the parts of S2L sub-LSPs that share hops, this information is the parts of S2L sub-LSPs that share hops, this information is
deduced from the explicit routes of other S2L sub-LSPs using explicit deduced from the explicit routes of other S2L sub-LSPs using explicit
route compression in SEROs. route compression in SEROs.
Explicit route compression is illustrated using the following figure. Explicit route compression is illustrated using Figure 1.
A A
| |
| |
B B
| |
| |
C----D----E C----D----E
| | | | | |
| | | | | |
F G H-------I F G H-------I
| |\ | | |\ |
| | \ | | | \ |
J K L M J K L M
| | | | | | | |
| | | | | | | |
N O P Q--R N O P Q--R
Figure 1. Explicit Route Compression Figure 1. Explicit Route Compression
Figure 1. shows a P2MP LSP with LSR A as the ingress LSR and six Figure 1. shows a P2MP LSP with LSR A as the ingress-LSR and six
egress LSRs: (F, N, O, P, Q and R). When all the six S2L sub-LSPs are egress LSRs: (F, N, O, P, Q and R). When all the six S2L sub-LSPs are
signaled in one Path message let us assume that the S2L sub-LSP to signaled in one Path message let us assume that the S2L sub-LSP to
LSR F is the first S2L sub-LSP and the rest are subsequent S2L sub- LSR F is the first S2L sub-LSP and the rest are subsequent S2L sub-
LSPs. Following is one way for the ingress LSR A to encode the S2L LSPs. The following encoding is one way for the ingress-LSR A to
sub-LSP explicit routes using compression: encode the S2L sub-LSP explicit routes using compression:
S2L sub-LSP-F: ERO = {B, E, D, C, F}, <S2L_SUB_LSP> object-F S2L sub-LSP-F: ERO = {B, E, D, C, F}, <S2L_SUB_LSP> object-F
S2L sub-LSP-N: SERO = {D, G, J, N}, <S2L_SUB_LSP> object-N S2L sub-LSP-N: SERO = {D, G, J, N}, <S2L_SUB_LSP> object-N
S2L sub-LSP-O: SERO = {E, H, K, O}, <S2L_SUB_LSP> object-O S2L sub-LSP-O: SERO = {E, H, K, O}, <S2L_SUB_LSP> object-O
S2L sub-LSP-P: SERO = {H, L, P}, <S2L_SUB_LSP> object-P, S2L sub-LSP-P: SERO = {H, L, P}, <S2L_SUB_LSP> object-P,
S2L sub-LSP-Q: SERO = {H, I, M, Q}, <S2L_SUB_LSP> object-Q, S2L sub-LSP-Q: SERO = {H, I, M, Q}, <S2L_SUB_LSP> object-Q,
S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R, S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R,
After LSR E processes the incoming Path message from LSR B it sends a After LSR E processes the incoming Path message from LSR B it sends a
Path message to LSR D with the S2L sub-LSP explicit routes encoded as Path message to LSR D with the S2L sub-LSP explicit routes encoded as
skipping to change at page 10, line 4 skipping to change at page 10, line 17
S2L sub-LSP-O: ERO = {H, K, O}, <S2L_SUB_LSP> object-O S2L sub-LSP-O: ERO = {H, K, O}, <S2L_SUB_LSP> object-O
S2L sub-LSP-P: SERO = {H, L, P}, S2L_SUB_LSP object-P, S2L sub-LSP-P: SERO = {H, L, P}, S2L_SUB_LSP object-P,
S2L sub-LSP-Q: SERO = {H, I, M, Q}, <S2L_SUB_LSP> object-Q, S2L sub-LSP-Q: SERO = {H, I, M, Q}, <S2L_SUB_LSP> object-Q,
S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R, S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R,
After LSR H processes the incoming Path message from E it sends a After LSR H processes the incoming Path message from E it sends a
Path message to LSR K, LSR L and LSR I. The encoding for the Path Path message to LSR K, LSR L and LSR I. The encoding for the Path
message to LSR K is as follows: message to LSR K is as follows:
S2L sub-LSP-O: ERO = {K, O}, <S2L_SUB_LSP> object-O S2L sub-LSP-O: ERO = {K, O}, <S2L_SUB_LSP> object-O
The encoding of the Path message sent by LSR H to LSR L is as The encoding of the Path message sent by LSR H to LSR L is as
follows: follows:
S2L sub-LSP-P: ERO = {L, P}, <S2L_SUB_LSP> object-P, S2L sub-LSP-P: ERO = {L, P}, <S2L_SUB_LSP> object-P,
Following is one way for LSR H to encode the S2L sub-LSP explicit The following encoding is one way for LSR H to encode the S2L sub-LSP
routes in the Path message sent to LSR I: explicit routes in the Path message sent to LSR I:
S2L sub-LSP-Q: ERO = {I, M, Q}, <S2L_SUB_LSP> object-Q, S2L sub-LSP-Q: ERO = {I, M, Q}, <S2L_SUB_LSP> object-Q,
S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R, S2L sub-LSP-R: SERO = {Q, R}, <S2L_SUB_LSP> object-R,
The explicit route encodings in the Path messages sent by LSRs D and The explicit route encodings in the Path messages sent by LSRs D and
Q are left as an exercise to the reader. Q are left as an exercise for the reader.
This compression mechanism reduces the Path message size. It also This compression mechanism reduces the Path message size. It also
reduces extra processing that can result if explicit routes are reduces extra processing that can result if explicit routes are
encoded from ingress to egress for each S2L sub-LSP. No assumptions encoded from ingress to egress for each S2L sub-LSP. No assumptions
are placed on the ordering of the subsequent S2L sub-LSPs and hence are placed on the ordering of the subsequent S2L sub-LSPs and hence
on the ordering of the SEROs in the Path message. All LSRs need to on the ordering of the SEROs in the Path message. All LSRs need to
process the ERO corresponding to the first S2L sub-LSP. A LSR needs process the ERO corresponding to the first S2L sub-LSP. An LSR needs
to process a S2L sub-LSP descriptor for a subsequent S2L sub-LSP only to process an S2L sub-LSP descriptor for a subsequent S2L sub-LSP
if the first hop in the corresponding SERO is a local address of that only if the first hop in the corresponding SERO is a local address of
LSR. The branch LSR that is the first hop of a SERO propagates the that LSR. The branch LSR that is the first hop of an SERO propagates
corresponding S2L sub-LSP downstream. the corresponding S2L sub-LSP downstream.
5. Path Message 5. Path Message
5.1. Path Message Format 5.1. Path Message Format
This section describes modifications made to the Path message format This section describes modifications made to the Path message format
as specified in [RFC3209] and [RFC3473]. The Path message is enhanced as specified in [RFC3209] and [RFC3473]. The Path message is enhanced
to signal one or more S2L sub-LSPs. This is done by including the S2L to signal one or more S2L sub-LSPs. This is done by including the S2L
sub-LSP descriptor list in the Path message as shown below. sub-LSP descriptor list in the Path message as shown below.
skipping to change at page 11, line 12 skipping to change at page 11, line 35
[ <ADMIN_STATUS> ] [ <ADMIN_STATUS> ]
[ <POLICY_DATA> ... ] [ <POLICY_DATA> ... ]
<sender descriptor> <sender descriptor>
[<S2L sub-LSP descriptor list>] [<S2L sub-LSP descriptor list>]
Following is the format of the S2L sub-LSP descriptor list. Following is the format of the S2L sub-LSP descriptor list.
<S2L sub-LSP descriptor list> ::= <S2L sub-LSP descriptor> <S2L sub-LSP descriptor list> ::= <S2L sub-LSP descriptor>
[ <S2L sub-LSP descriptor list> ] [ <S2L sub-LSP descriptor list> ]
<S2L sub-LSP descriptor> ::= <S2L_SUB_LSP> [ <P2MP <S2L sub-LSP descriptor> ::= <S2L_SUB_LSP>
SECONDARY_EXPLICIT_ROUTE> ] [ <P2MP SECONDARY_EXPLICIT_ROUTE> ]
Each LSR MUST use the common objects in the Path message and the S2L Each LSR MUST use the common objects in the Path message and the S2L
sub-LSP descriptors to process each S2L sub-LSP represented by the sub-LSP descriptors to process each S2L sub-LSP represented by the
<S2L_SUB_LSP> object and the SECONDARY-/EXPLICIT_ROUTE object S2L_SUB_LSP object and the SECONDARY-/EXPLICIT_ROUTE object
combination. combination.
The first <S2L_SUB_LSP> object's explicit route is specified by the Per the definition of <S2L sub-LSP descriptor>, each S2L_SUB_LSP
ERO. Explicit routes of subsequent S2L sub-LSPs are specified by the object MAY be followed by a corresponding SERO. The first S2L_SUB_LSP
corresponding SERO. A SERO corresponds to the following <S2L_SUB_LSP> object is a special case, and its explicit route is specified by the
object. ERO. Therefore, the first S2L_SUB_LSP object SHOULD NOT be followed
by an SERO, and if one is present it MUST be ignored.
The RRO in the sender descriptor contains the hops traversed by the The RRO in the sender descriptor contains the upstream hops traversed
Path message and applies to all the S2L sub-LSPs signaled in the Path by the Path message and applies to all the S2L sub-LSPs signaled in
message. the Path message.
An IF_ID RSVP_HOP object MUST be used on links where there is not a
one-to-one association of a control channel to a data channel
[RFC3471]. An RSVP_HOP object defined in [RFC2205] SHOULD be used
otherwise.
Path message processing is described in the next section. Path message processing is described in the next section.
5.2. Path Message Processing 5.2. Path Message Processing
The ingress-LSR initiates the set up of an S2L sub-LSP to each The ingress-LSR initiates the setup of an S2L sub-LSP to each egress-
egress-LSR that is the destination of the P2MP LSP. Each S2L sub-LSP LSR that is a destination of the P2MP LSP. Each S2L sub-LSP is
is associated with the same P2MP LSP using common P2MP SESSION object associated with the same P2MP LSP using common P2MP SESSION object
and <Sender Address, LSP-ID> fields in the P2MP SENDER_TEMPLATE and <Sender Address, LSP-ID> fields in the P2MP SENDER_TEMPLATE
object. Hence it can be combined with other S2L sub-LSPs to form a object. Hence it can be combined with other S2L sub-LSPs to form a
P2MP LSP. Another S2L sub-LSP belonging to the same instance of this P2MP LSP. Another S2L sub-LSP belonging to the same instance of this
S2L sub-LSP (i.e. the same P2MP LSP) shares resources with this S2L S2L sub-LSP (i.e. the same P2MP LSP) SHOULD share resources with
sub-LSP. The session corresponding to the P2MP TE tunnel is this S2L sub-LSP. The session corresponding to the P2MP TE tunnel is
determined based on the P2MP SESSION object. Each S2L sub-LSP is determined based on the P2MP SESSION object. Each S2L sub-LSP is
identified using the <S2L_SUB_LSP> object. Explicit routing for the identified using the S2L_SUB_LSP object. Explicit routing for the S2L
S2L sub-LSPs is achieved using the ERO and SEROs. sub-LSPs is achieved using the ERO and SEROs.
As mentioned earlier, it is possible to signal S2L sub-LSPs for a As mentioned earlier, it is possible to signal S2L sub-LSPs for a
given P2MP LSP in one or more Path messages and a given Path message given P2MP LSP in one or more Path messages and a given Path message
can contain one or more S2L sub-LSPs. A LSR that supports RSVP-TE can contain one or more S2L sub-LSPs. An LSR that supports RSVP-TE
signaled P2MP LSPs MUST be able to receive and process multiple Path signaled P2MP LSPs MUST be able to receive and process multiple Path
messages for the same P2MP LSP and multiple S2L sub-LSPs in one Path messages for the same P2MP LSP and multiple S2L sub-LSPs in one Path
message. This implies that such an LSR MUST be able to receive and message. This implies that such an LSR MUST be able to receive and
process all objects listed in section 20. process all objects listed in section 19.
5.2.1. Multiple Path Messages 5.2.1. Multiple Path Messages
As described in section 3, either the <EXPLICIT_ROUTE> <S2L_SUB_LSP> As described in section 4, either the < [<EXPLICIT_ROUTE>]
or the <P2MP SECONDARY_EXPLICIT_ROUTE> <S2L_SUB_LSP> tuple is used to <S2L_SUB_LSP> > or the < [<P2MP SECONDARY_EXPLICIT_ROUTE>]
specify a S2L sub-LSP. Multiple Path messages can be used to signal a <S2L_SUB_LSP> > tuple is used to specify an S2L sub-LSP. Multiple
P2MP LSP. Each Path message can signal one or more S2L sub-LSPs. If a Path messages can be used to signal a P2MP LSP. Each Path message can
Path message contains only one S2L sub-LSP, each LSR along the S2L signal one or more S2L sub-LSPs. If a Path message contains only one
sub-LSP follows [RFC3209] procedures for processing the Path message S2L sub-LSP, each LSR along the S2L sub-LSP follows [RFC3209]
besides the <S2L_SUB_LSP> object processing described in this procedures for processing the Path message besides the S2L_SUB_LSP
document. object processing described in this document.
Processing of Path messages containing more than one S2L sub-LSP is Processing of Path messages containing more than one S2L sub-LSP is
described in Section 5.2.2. described in Section 5.2.2.
An ingress LSR may use multiple Path messages for signaling a P2MP An ingress-LSR MAY use multiple Path messages for signaling a P2MP
LSP. This may be because a single Path message may not be large LSP. This may be because a single Path message may not be large
enough to signal the P2MP LSP. Or it may be while adding leaves to enough to signal the P2MP LSP. Or it may be while adding leaves to
the P2MP LSP the new leaves are signaled in a new Path message. Or an the P2MP LSP the new leaves are signaled in a new Path message. Or an
ingress LSR MAY choose to break the P2MP tree into separate ingress LSR MAY choose to break the P2MP tree into separate
manageable P2MP trees. These trees share the same root and may share manageable P2MP trees. These trees share the same root and may share
the trunk and certain branches. The scope of this management the trunk and certain branches. The scope of this management
decomposition of P2MP trees is bounded by a single tree (the P2MP decomposition of P2MP trees is bounded by a single tree (the P2MP
Tree) and multiple trees with a single leaf each (S2L sub-LSPs). Per Tree) and multiple trees with a single leaf each (S2L sub-LSPs). Per
[RFC4461], a P2MP LSP MUST have consistent attributes across all [RFC4461], a P2MP LSP MUST have consistent attributes across all
portions of a tree. This implies that each Path message that is used portions of a tree. This implies that each Path message that is used
to signal a P2MP LSP is signaled using the same signaling attributes to signal a P2MP LSP is signaled using the same signaling attributes
with the exception of the S2L sub-LSP information and Sub-Group with the exception of the S2L sub-LSP descriptors and Sub-Group
identifiers. identifier.
The resulting sub-LSPs from the different Path messages belonging to The resulting sub-LSPs from the different Path messages belonging to
the same P2MP LSP SHOULD share labels and resources where they share the same P2MP LSP SHOULD share labels and resources where they share
hops to prevent multiple copies of the data being sent. hops to prevent multiple copies of the data being sent.
In certain cases a transit LSR may need to generate multiple Path In certain cases a transit LSR may need to generate multiple Path
messages to signal state corresponding to a single received Path messages to signal state corresponding to a single received Path
message. For instance ERO expansion may result in an overflow of the message. For instance ERO expansion may result in an overflow of the
resultant Path message. In this case the message can be decomposed resultant Path message. In this case the message can be decomposed
into multiple Path messages such that each of the messages carry a into multiple Path messages such that each message carries a subset
subset of the X2L sub-tree carried by the incoming message. of the X2L sub-tree carried by the incoming message.
Multiple Path messages generated by an LSR that signal state for the Multiple Path messages generated by an LSR that signal state for the
same P2MP LSP are signaled with the same SESSION object and have the same P2MP LSP are signaled with the same SESSION object and have the
same <Source address, LSP-ID> in the SENDER_TEMPLATE object. In order same <Source address, LSP-ID> in the SENDER_TEMPLATE object. In order
to disambiguate these Path messages a <Sub-Group Originator ID, sub- to disambiguate these Path messages a <Sub-Group Originator ID, Sub-
Group ID> tuple is introduced (also referred to as the Sub-Group Group ID> tuple is introduced (also referred to as the Sub-Group
field) and encoded in the SENDER_TEMPLATE object. Multiple Path fields) and encoded in the SENDER_TEMPLATE object. Multiple Path
messages generated by a LSR to signal state for the same P2MP LSP messages generated by an LSR to signal state for the same P2MP LSP
have the same Sub-Group Originator ID and have a different sub-Group have the same Sub-Group Originator ID and have a different sub-Group
ID. The Sub-Group Originator ID MUST be set to the TE Router ID of ID. The Sub-Group Originator ID MUST be set to the TE Router ID of
the LSR that originates the Path message. This is either the ingress the LSR that originates the Path message. Cases when a transit LSR
LSR or a LSR which re-originates the Path message with its own Sub- may change the Sub-Group Originator ID of an incoming Path message
Group Originator ID. Cases when a transit LSR may change the Sub- are described below. The Sub-Group Originator ID is globally unique.
Group Originator ID of an incoming Path message are described below.
The <Sub-Group Originator ID, sub-Group ID> tuple is globally unique.
The sub-Group ID space is specific to the Sub-Group Originator ID. The sub-Group ID space is specific to the Sub-Group Originator ID.
Therefore the combination <Sub-Group Originator ID, sub-Group ID> is
network-wide unique. Also, a router that changes the Sub-Group
originator ID of an incoming Path message MUST use the same value of
the Sub-Group Originator ID for all outgoing Path messages, for a
particular P2MP LSP, and SHOULD not vary it during the life of the
P2MP LSP.
5.2.2. Multiple S2L Sub-LSPs in one Path message 5.2.2. Multiple S2L Sub-LSPs in one Path message
The S2L sub-LSP descriptor list allows the signaling of one or more The S2L sub-LSP descriptor list allows the signaling of one or more
S2L sub-LSPs in one Path message. It is possible to signal multiple S2L sub-LSPs in one Path message. Each S2L sub-LSP descriptor
<S2L_SUB_LSP> object and ERO/SERO combinations in a single Path describes a single S2L sub-LSP.
message. Note that these two objects differentiate a S2L sub-LSP.
All LSRs MUST process the ERO corresponding to the first S2L sub-LSP All LSRs MUST process the ERO corresponding to the first S2L sub-LSP
if the ERO is present. If one or more SEROs are present an ERO MUST if the ERO is present. If one or more SEROs are present an ERO MUST
be present. The first S2L sub-LSP MUST be propagated in a Path be present. The first S2L sub-LSP MUST be propagated in a Path
message by each LSR along the explicit route specified by the ERO, if message by each LSR along the explicit route specified by the ERO, if
the ERO is present. Else it MUST be propagated using hop-by-hop the ERO is present. Else it MUST be propagated using hop-by-hop
routing towards the destination identified by the <S2L_SUB_LSP> routing towards the destination identified by the S2L_SUB_LSP object.
object.
A LSR MUST process a S2L sub-LSP descriptor for a subsequent S2L sub- An LSR MUST process a S2L sub-LSP descriptor for a subsequent S2L
LSP as follows: sub-LSP as follows:
If the <S2L_SUB_LSP> object is followed by an SERO, the LSR MUST If the S2L_SUB_LSP object is followed by an SERO, the LSR MUST
check the first hop in the SERO: check the first hop in the SERO:
- If the first hop of the SERO identifies a local address of the - If the first hop of the SERO identifies a local address of the
LSR, and the LSR is also the egress identified by the LSR, and the LSR is also the egress identified by the
<S2L_SUB_LSP> object, the descriptor MUST NOT be propagated S2L_SUB_LSP object, the descriptor MUST NOT be propagated
downstream, but the SERO may be used for egress control per downstream, but the SERO may be used for egress control per
[RFC4003]. [RFC4003].
- If the first hop of the SERO identifies a local address of the - If the first hop of the SERO identifies a local address of the
LSR, and the LSR is not the egress as identified by the LSR, and the LSR is not the egress as identified by the
<S2L_SUB_LSP> object the S2L sub-LSP descriptor MUST be S2L_SUB_LSP object, the S2L sub-LSP descriptor MUST be
included in a Path message sent to the next-hop determined included in a Path message sent to the next-hop determined
from the SERO. from the SERO.
- If the first hop of the SERO is not a local address of the LSR - If the first hop of the SERO is not a local address of the LSR,
the S2L sub-LSP descriptor MUST be included in the Path message the S2L sub-LSP descriptor MUST be included in the Path message
sent to LSR that is the next hop to reach the first hop in the sent to the LSR that is the next hop to reach the first hop in
SERO. This next hop is determined by using the ERO or other the SERO. This next hop is determined by using the ERO or other
SEROs that encode the path to the SERO's first hop. SEROs that encode the path to the SERO's first hop.
If the <S2L_SUB_LSP> object is not followed by an SERO, the LSR MUST If the S2L_SUB_LSP object is not followed by an SERO, the LSR MUST
examine the <S2L_SUB_LSP> object: examine the S2L_SUB_LSP object:
- If this LSR is the egress as identified by the - If this LSR is the egress as identified by the
<S2L_SUB_LSP> object, the S2L sub-LSP descriptor MUST S2L_SUB_LSP object, the S2L sub-LSP descriptor MUST
NOT be propagated downstream. NOT be propagated downstream.
- If this LSR is not the egress as identified by the - If this LSR is not the egress as identified by the
<S2L_SUB_LSP> object, the LSR MUST make a routing decision S2L_SUB_LSP object, the LSR MUST make a routing decision
to determine the next hop towards the egress, and MUST to determine the next hop towards the egress, and MUST
include the S2L sub-LSP descriptor in a Path message sent include the S2L sub-LSP descriptor in a Path message sent
to the next-hop towards the egress. In this case, the LSR to the next-hop towards the egress. In this case, the LSR
MAY insert an SERO into the S2L sub-LSP descriptor. MAY insert an SERO into the S2L sub-LSP descriptor.
Hence a branch LSR MUST only propagate the relevant S2L sub-LSP Hence a branch LSR MUST only propagate the relevant S2L sub-LSP
descriptors on each downstream link. A S2L sub-LSP descriptor list descriptors to each downstream hop. An S2L sub-LSP descriptor list
that is propagated on a downstream link MUST only contain those S2L that is propagated on a downstream link MUST only contain those S2L
sub-LSPs that are routed using that link. This processing MAY result sub-LSPs that are routed using that hop. This processing MAY result
in a subsequent S2L sub-LSP in an incoming Path message to become the in a subsequent S2L sub-LSP in an incoming Path message becoming the
first S2L sub-LSP in an outgoing Path message. first S2L sub-LSP in an outgoing Path message.
Note that if one or more SEROs contain loose hops, expansion of such Note that if one or more SEROs contain loose hops, expansion of such
loose hops MAY result in overflowing the Path message size. Section loose hops MAY result in overflowing the Path message size. Section
5.2.3 describes how signaling of the set of S2L sub-LSPs can be split 5.2.3 describes how signaling of the set of S2L sub-LSPs can be split
in more than one Path message. across more than one Path message.
The RECORD_ROUTE Object (RRO) contains the hops traversed by the Path The RECORD_ROUTE Object (RRO) contains the hops traversed by the Path
message and applies to all the S2L sub-LSPs signaled in the Path message and applies to all the S2L sub-LSPs signaled in the Path
message. A transit LSR MUST append its address in an incoming RRO and message. A transit LSR MUST append its address in an incoming RRO and
propagate it downstream. A branch LSR MUST form a new RRO for each of propagate it downstream. A branch LSR MUST form a new RRO for each of
the outgoing Path messages by copying the RRO from the incoming Path the outgoing Path messages by copying the RRO from the incoming Path
message and appending its address. Each such updated RRO MUST be message and appending its address. Each such updated RRO MUST be
formed using the rules in [RFC3209]. formed using the rules in [RFC3209] updated by [RFC3473] as
appropriate.
If a LSR is unable to support a S2L sub-LSP in a Path message, a If an LSR is unable to support an S2L sub-LSP in a Path message (for
PathErr message MUST be sent for the impacted S2L sub-LSP, and normal example, it is unable to route towards the destination using the
processing of the rest of the P2MP LSP SHOULD continue. The default SERO), a PathErr message MUST be sent for the impacted S2L sub-LSP,
behavior is that the remainder of the LSP is not impacted (that is, and normal processing of the rest of the P2MP LSP SHOULD continue.
all other branches are allowed to set up) and the failed branches are The default behavior is that the remainder of the LSP is not impacted
reported in PathErr messages in which the Path_State_Removed flag (that is, all other branches are allowed to set up) and the failed
MUST NOT be set. However, the ingress LSR may set a LSP Integrity branches are reported in PathErr messages in which the
flag to request that if there is a setup failure on any branch the Path_State_Removed flag MUST NOT be set. However, the ingress-LSR
entire LSP should fail to set up. This is described further in may set an LSP Integrity flag to request that if there is a setup
section 12. failure on any branch the entire LSP should fail to set up. This is
described further in sections 5.2.4 and 11.
5.2.3. Transit Fragmentation 5.2.3. Transit Fragmentation of Path State Information
In certain cases a transit LSR may need to generate multiple Path In certain cases a transit LSR may need to generate multiple Path
messages to signal state corresponding to a single received Path messages to signal state corresponding to a single received Path
message. For instance ERO expansion may result in an overflow of the message. For instance ERO expansion may result in an overflow of the
resultant Path message. It is desirable not to rely on IP resultant Path message. RSVP [RFC2205] disallows the use of IP
fragmentation in this case. In order to achieve this, the multiple fragmentation and thus IP fragmentation MUST be avoided in this case.
Path messages generated by the transit LSR, are signaled with the In order to achieve this, the multiple Path messages generated by the
Sub-Group Originator ID set to the TE Router ID of the transit LSR transit LSR, are signaled with the Sub-Group Originator ID set to the
and a distinct sub-Group ID for each Path message. Thus each distinct TE Router ID of the transit LSR and a distinct Sub-Group ID for each
Path message that is generated by the transit LSR for the P2MP LSP Path message. Thus each distinct Path message that is generated by
carries a distinct <Sub-Group Originator ID, Sub-Group ID> tuple. the transit LSR for the P2MP LSP carries a distinct <Sub-Group
Originator ID, Sub-Group ID> tuple.
When multiple Path messages are used by an ingress or transit node, When multiple Path messages are used by an ingress or transit node,
each Path message SHOULD be identical with the exception of the S2L each Path message SHOULD be identical with the exception of the S2L
sub-LSP related information (e.g., SERO), message and hop information sub-LSP related descriptor (e.g., SERO), message and hop information
(e.g., INTEGRITY, MESSAGE_ID and RSVP_HOP), and the sub-group fields (e.g., INTEGRITY, MESSAGE_ID and RSVP_HOP), and the sub-group fields
of the SENDER_TEMPLATE objects. Except when performing a make- of the SENDER_TEMPLATE objects. Except when performing a make-
before-break operation as specified in section 14.1, the tunnel before-break operation as specified in section 14.1, the tunnel
sender address and LSP ID fields MUST be the same in each message, sender address and LSP ID fields MUST be the same in each message,
and for transit nodes, the same as the values in the received Path and for transit nodes, the same as the values in the received Path
message. message.
As described above one case in which the Sub-Group Originator ID of a As described above one case in which the Sub-Group Originator ID of a
received Path message is changed is that of transit fragmentation. received Path message is changed is that of fragmentation of a Path
Another case is when the Sub-Group Originator ID of a received Path message at a transit node. Another case is when the Sub-Group
message may be changed in the outgoing Path message and set to that Originator ID of a received Path message may be changed in the
of the LSR originating the Path message based on a local policy. For outgoing Path message and set to that of the LSR originating the Path
instance a LSR may decide to always change the Sub-Group Originator message based on a local policy. For instance an LSR may decide to
ID while performing ERO expansion. The Sub-Group ID MUST not be always change the Sub-Group Originator ID while performing ERO
changed if the Sub-Group Originator ID is not being changed. expansion. The Sub-Group ID MUST not be changed if the Sub-Group
Originator ID is not changed.
5.2.4. Control of Branch Fate Sharing 5.2.4. Control of Branch Fate Sharing
An ingress LSR can control the behavior of an LSP if there is a An ingress-LSR can control the behavior of an LSP if there is a
failure during LSP setup or after an LSP has been established. The failure during LSP setup or after an LSP has been established. The
default behavior is that only the branches downstream of the failure default behavior is that only the branches downstream of the failure
are not established, but the ingress may request 'LSP integrity' such are not established, but the ingress may request 'LSP integrity' such
that any failure anywhere within the LSP tree causes the entire P2MP that any failure anywhere within the LSP tree causes the entire P2MP
LSP to fail. LSP to fail.
The ingress LSP may request 'LSP integrity' by setting bit (TBA) of The ingress LSP may request 'LSP integrity' by setting bit TBD of the
the Attributes Flags TLV. The bit is set if LSP integrity is Attributes Flags TLV. (RFC Editor, please replace "TBD" with the bit
required. number allocated by IANA per section 20.4. Please remove this note.)
The bit is set if LSP integrity is required.
It is RECOMMENDED to use the LSP_REQUIRED_ATTRIBUTES Object. It is RECOMMENDED to use the LSP_REQUIRED_ATTRIBUTES Object
[RFC4420].
A branch LSR that supports the Attributes Flags TLV and recognizes A branch LSR that supports the Attributes Flags TLV and recognizes
this bit MUST support LSP integrity or reject the LSP setup with a this bit MUST support LSP integrity or reject the LSP setup with a
PathErr message carrying the error "Routing Error"/"Unsupported LSP PathErr message carrying the error "Routing Error"/"Unsupported LSP
Integrity" Integrity"
5.3. Grafting 5.3. Grafting
The operation of adding egress LSR(s) to an existing P2MP LSP is The operation of adding egress-LSR(s) to an existing P2MP LSP is
termed as grafting. This operation allows egress nodes to join a P2MP termed as grafting. This operation allows egress nodes to join a P2MP
LSP at different points in time. LSP at different points in time.
There are two methods to add S2L sub-LSPs to a P2MP LSP. The first There are two methods to add S2L sub-LSPs to a P2MP LSP. The first
is to add new S2L sub-LSPs to the P2MP LSP by adding them to an is to add new S2L sub-LSPs to the P2MP LSP by adding them to an
existing Path message and refreshing the entire Path message. Path existing Path message and refreshing the entire Path message. Path
message processing described in section 4 results in adding these S2L message processing described in section 4 results in adding these S2L
sub-LSPs to the P2MP LSP. Note that as a result of adding one or more sub-LSPs to the P2MP LSP. Note that as a result of adding one or more
S2L sub-LSPs to a Path message the ERO compression encoding may have S2L sub-LSPs to a Path message the ERO compression encoding may have
to be recomputed. to be recomputed.
skipping to change at page 17, line 20 skipping to change at page 17, line 40
<SE flow descriptor> ::= <FLOWSPEC> <SE filter spec list> <SE flow descriptor> ::= <FLOWSPEC> <SE filter spec list>
<SE filter spec list> ::= <SE filter spec> <SE filter spec list> ::= <SE filter spec>
| <SE filter spec list> <SE filter spec> | <SE filter spec list> <SE filter spec>
The FF flow descriptor and SE filter spec are modified as follows to The FF flow descriptor and SE filter spec are modified as follows to
identify the S2L sub-LSPs that they correspond to: identify the S2L sub-LSPs that they correspond to:
<FF flow descriptor> ::= [ <FLOWSPEC> ] <FILTER_SPEC> <LABEL> <FF flow descriptor> ::= [ <FLOWSPEC> ] <FILTER_SPEC> <LABEL>
[ <RECORD_ROUTE> ] [ <S2L sub-LSP descriptor [ <RECORD_ROUTE> ]
list> ] [ <S2L sub-LSP flow descriptor list> ]
<SE filter spec> ::= <FILTER_SPEC> <LABEL> [ <RECORD_ROUTE> ] <SE filter spec> ::= <FILTER_SPEC> <LABEL> [ <RECORD_ROUTE> ]
[ <S2L sub-LSP descriptor list> ] [ <S2L sub-LSP flow descriptor list> ]
<S2L sub-LSP descriptor list> ::= <S2L sub-LSP descriptor> <S2L sub-LSP flow descriptor list> ::=
[ <S2L sub-LSP descriptor list> ] <S2L sub-LSP flow descriptor>
[ <S2L sub-LSP flow descriptor list> ]
<S2L sub-LSP descriptor> ::= <S2L_SUB_LSP> [ <P2MP <S2L sub-LSP flow descriptor> ::= <S2L_SUB_LSP>
SECONDARY_EXPLICIT_ROUTE> ] [ <P2MP_SECONDARY_RECORD_ROUTE> ]
FILTER_SPEC is defined in section 20.4. FILTER_SPEC is defined in section 19.4.
The S2L sub-LSP descriptor has the same format as in section 4.1 with The S2L sub-LSP flow descriptor has the same format as S2L sub-LSP
the difference that a P2MP_SECONDARY_RECORD_ROUTE object is used in descriptor in section 4.1 with the difference that a
place of a P2MP SECONDARY_EXPLICIT_ROUTE object. The P2MP_SECONDARY_RECORD_ROUTE object is used in place of a P2MP
P2MP_SECONDARY_RECORD_ROUTE objects follow the same compression SECONDARY_EXPLICIT_ROUTE object. The P2MP_SECONDARY_RECORD_ROUTE
mechanism as the P2MP SECONDARY_EXPLICIT_ROUTE objects. Note that objects follow the same compression mechanism as the P2MP
that a Resv message can signal multiple S2L sub-LSPs that may belong SECONDARY_EXPLICIT_ROUTE objects. Note that that a Resv message can
to the same FILTER_SPEC object or different FILTER_SPEC objects. The signal multiple S2L sub-LSPs that may belong to the same FILTER_SPEC
same label SHOULD be allocated if the <Sender Address, LSP-ID> fields object or different FILTER_SPEC objects. The same label SHOULD be
of the FILTER_SPEC object are the same. allocated if the <Sender Address, LSP-ID> fields of the FILTER_SPEC
object are the same.
However different upstream labels are allocated if the <Sender However different labels MUST be allocated if the <Sender Address,
Address, LSP-ID> of the FILTER_SPEC object is different as that LSP-ID> of the FILTER_SPEC object is different as that implies that
implies different P2MP LSP. the FILTER_SPEC refers to a different P2MP LSP.
6.2. Resv Message Processing 6.2. Resv Message Processing
The egress LSR MUST follow normal RSVP procedures while originating a The egress LSR MUST follow normal RSVP procedures while originating a
Resv message. The Resv message carries the label allocated by the Resv message. The format of Resv messages is as defined in Section
6.1. As usual, the Resv message carries the label allocated by the
egress LSR. egress LSR.
A node upstream of the egress node MUST allocate its own label and A node upstream of the egress node MUST allocate its own label and
pass it in the Resv message upstream. The node MAY combine multiple pass it upstream in the Resv message. The node MAY combine multiple
flow descriptors, from different Resv messages received from flow descriptors, from different Resv messages received from
downstream, in one Resv message sent upstream. A Resv message MUST downstream, in one Resv message sent upstream. A Resv message MUST
NOT be sent upstream until at least one Resv message has been NOT be sent upstream until at least one Resv message has been
received from a downstream neighbor. When the integrity bit is set in received from a downstream neighbor. When the integrity bit is set in
the LSP_REQUIRED_ATTRIBUTE object, no Resv message MUST be sent the LSP_REQUIRED_ATTRIBUTE object, Resv message MUST NOT be sent
upstream until all Resv messages have been received from the upstream until all Resv messages have been received from the
downstream neighbors. downstream neighbors.
Each FF flow descriptor or SE filter spec sent upstream in a Resv Each FF flow descriptor or SE filter spec sent upstream in a Resv
message includes a S2L sub-LSP descriptor list. Each such FF flow message includes a S2L sub-LSP descriptor list. Each such FF flow
descriptor or SE filter spec for the same P2MP LSP (whether on one or descriptor or SE filter spec for the same P2MP LSP (whether on one or
multiple Resv messages) on the same Resv MUST be allocated the same multiple Resv messages) on the same Resv MUST be allocated the same
label, and FF flow descriptors or SE filter specs SHOULD use the same label, and FF flow descriptors or SE filter specs SHOULD use the same
label across multiple Resv messages. label across multiple Resv messages.
This label is associated by that node with all the labels received This label is associated by that node with all the labels received
from downstream Resv messages for that P2MP LSP. Note that a transit from downstream Resv messages for that P2MP LSP. Note that a transit
node may become a replication point in the future when a branch is node may become a replication point in the future when a branch is
attached to it. Hence this results in the setup of a P2MP LSP from attached to it. Hence this results in the setup of a P2MP LSP from
the ingress-LSR to the egress LSRs. the ingress-LSR to the egress-LSRs.
The ingress LSR may need to understand when all desired egresses have The ingress-LSR may need to understand when all desired egresses have
been reached. This is achieved using <S2L_SUB_LSP> objects. been reached. This is achieved using S2L_SUB_LSP objects.
Each branch node can potentially send one Resv message upstream for Each branch node MAY forward a single Resv message upstream for each
each of the downstream receivers. This MAY result in overflowing the received Resv message from a downstream receiver. Note that there may
Resv message, particularly when considering that the number of be a large number of Resv messages at and close to the ingress LSR
messages increases the closer the branch node is to the ingress of for an LSP with many receivers. A branch LSR SHOULD combine Resv
the P2MP LSP. state from multiple receivers into a single Resv message to be sent
upstream (see section 6.2.1), but note that this may result in
overflowing the Resv message particularly as the number of receivers
downstream of any branch LSR increases as the LSR is closer to the
ingress LSR. Thus, a branch LSR MAY choose to send more than one Resv
message upstream and partition the Resv state between the messages.
Transit nodes MUST replace the Sub-Group ID fields received in the When a transit node set the Sub-Group Originator field in a Path
FILTER_SPEC objects with the value that was received in the Sub-Group message it MUST replace the Sub-Group fields received in the
ID field of the Path message from the upstream neighbor, when the FILTER_SPEC objects of any associated Resv messages with the value
node set the Sub-Group Originator field in the associated Path that it originally received in the Sub-Group fields of the Path
message. ResvErr messages generation is unmodified. Nodes message from the upstream neighbor.
propagating a received ResvErr message MUST use the Sub-Group field
values carried in the corresponding Resv message. ResvErr message generation is unmodified. Nodes propagating a
received ResvErr message MUST use the Sub-Group field values carried
in the corresponding Resv message.
6.2.1. Resv Message Throttling 6.2.1. Resv Message Throttling
A branch node may have to send the Resv message being sent upstream A branch node may have to send a revised Resv message upstream
whenever there is a change in a Resv message for a S2L sub-LSP whenever there is a change in a Resv message for an S2L sub-LSP
received from one of the downstream neighbors. This can result in received from one of the downstream neighbors. This can result in
excessive Resv messages sent upstream,particularly when the S2L sub- excessive Resv messages sent upstream,particularly when the S2L sub-
LSPs are established for the first time. In order to mitigate this LSPs are first established. In order to mitigate this situation,
situation, branch nodes can limit their transmission of Resv branch nodes can limit their transmission of Resv messages.
messages. Specifically, in the case where the only change being sent Specifically, in the case where the only change being sent in a Resv
in a Resv message is in one or more SRRO objects, the branch node message is in one or more SRRO objects, the branch node SHOULD
SHOULD transmit the Resv message only after a delay time has passed transmit the Resv message only after a delay time has passed since
since the transmission of the previous Resv message for the same the transmission of the previous Resv message for the same session.
session. This delayed Resv message SHOULD include SRROs for all This delayed Resv message SHOULD include SRROs for all branches. A
branches. Specific mechanisms for Resv message throttling are suggested value for the delay time is thirty seconds. Specific
mechanisms for Resv message throttling and delay timer settings are
implementation dependent and are outside the scope of this document. implementation dependent and are outside the scope of this document.
6.3. Record Routing 6.3. Route Recording
6.3.1. RRO Processing 6.3.1. RRO Processing
A Resv message contains a record route per S2L sub-LSP that is being A Resv message for a P2P LSP contains a recorded route if the ingress
signaled by the Resv message if the sender node requests route LSR requested route recording by including an RRO in the original
recording by including a RRO in the Path message. The same rule is Path message. The same rule is used during signaling of P2MP LSPs.
used during signaling of P2MP LSP i.e. insertion of the RRO in the That is, inclusion of an RRO in the Path message used to signal one
Path message used to signal one or more S2L sub-LSP triggers the or more S2L sub-LSPs triggers the inclusion of a recorded route for
inclusion of an RRO for each sub-LSP. each sub-LSP in the Resv message.
The record route of the first S2L sub-LSP is encoded in the RRO. The recorded route of the first S2L sub-LSP is encoded in the RRO.
Additional RROs for the subsequent S2L sub-LSPs are referred to as Additional recorded routes for the subsequent S2L sub-LSPs are
P2MP_SECONDARY_RECORD_ROUTE objects (SRROs). Their format is encoded in P2MP_SECONDARY_RECORD_ROUTE objects (SRROs). Their format
specified in section 20.5. The ingress node then receives the RRO and is specified in section 19.5. Each S2L_SUB_LSP object in a Resv is
possibly the SRRO corresponding to each subsequent S2L sub-LSP. Each associated with an RRO or SRRO. The first S2L_SUB_LSP object (for the
<S2L_SUB_LSP> object is followed by the RRO/SRRO. The ingress node first S2L sub-LSP) is associated with the RRO. Subsequent S2L_SUB_LSP
can then determine the record route corresponding to a particular S2L objects (for subsequent S2L sub-LSPs) are each followed by an SRRO
sub-LSP. The RRO and SRROs can be used to construct the end to end that contains the recorded route for that S2L sub-LSP from the leaf
Path for each S2L sub-LSP. to a branch. The ingress node can then use the RRO and SRROs to
determine the end-to-end path for each S2L sub-LSP.
6.4. Reservation Style 6.4. Reservation Style
Considerations about the reservation style in a Resv message apply as Considerations about the reservation style in a Resv message apply as
described in [RFC3209]. The reservation style in the Resv messages described in [RFC3209]. The reservation style in the Resv messages
can either be FF or SE. All P2MP LSPs that belong to the same P2MP can be either FF or SE. All P2MP LSPs that belong to the same P2MP
Tunnel MUST be signaled with the same reservation style. Irrespective Tunnel MUST be signaled with the same reservation style. Irrespective
of whether the reservation style is FF or SE, the S2L sub-LSPs that of whether the reservation style is FF or SE, the S2L sub-LSPs that
belong to the same P2MP LSP SHOULD share labels where they share belong to the same P2MP LSP SHOULD share labels where they share
hops. If the S2L sub-LSPs that belong to the same P2MP LSP share hops. If the S2L sub-LSPs that belong to the same P2MP LSP share
labels then they MUST share resources. The S2L sub-LSPs that belong labels then they MUST share resources. If the reservation style is FF
to different P2MP LSP MUST NOT share labels. If the reservation style then S2L sub-LSPs that belong to different P2MP LSPs MUST NOT share
is FF then S2L sub-LSPs that belong to different P2MP LSP MUST NOT resources or labels. If the reservation style is SE then S2L sub-LSPs
share resources. If the reservation style is SE than S2L sub-LSPs that belong to different P2MP LSPs and the same P2MP Tunnel SHOULD
that belong to different P2MP LSP and the same P2MP Tunnel SHOULD share resources where they share hops, but MUST not share labels in
share resources where they share hops, but MUST not share labels. packet environments.
7. PathTear Message 7. PathTear Message
7.1. PathTear Message Format 7.1. PathTear Message Format
The format of the PathTear message is as follows: The format of the PathTear message is as follows:
<PathTear Message> ::= <Common Header> [ <INTEGRITY> ] <PathTear Message> ::= <Common Header> [ <INTEGRITY> ]
[ [ <MESSAGE_ID_ACK> | [ [ <MESSAGE_ID_ACK> |
<MESSAGE_ID_NACK> ... ] <MESSAGE_ID_NACK> ... ]
[ <MESSAGE_ID> ] [ <MESSAGE_ID> ]
<SESSION> <RSVP_HOP> <SESSION> <RSVP_HOP>
[ <sender descriptor> ] [ <sender descriptor> ]
[ <S2L sub-LSP list> ] [ <S2L sub-LSP descriptor list> ]
<S2L sub-LSP list> ::= <S2L_SUB_LSP> [ <S2L sub-LSP list> ] <S2L sub-LSP descriptor list> ::= <S2L_SUB_LSP>
[ <S2L sub-LSP descriptor list> ]
The definition of <sender descriptor> is not changed by this The definition of <sender descriptor> is not changed by this
document. document.
7.2. Pruning 7.2. Pruning
The operation of removing egress LSR(s) from an existing P2MP LSP is The operation of removing egress-LSR(s) from an existing P2MP LSP is
termed as pruning. This operation allows egress nodes to be removed termed as pruning. This operation allows egress nodes to be removed
from a P2MP LSP at different points in time. This section describes from a P2MP LSP at different points in time. This section describes
the mechanisms to perform pruning. the mechanisms to perform pruning.
7.2.1. Implicit S2L Sub-LSP Teardown 7.2.1. Implicit S2L Sub-LSP Teardown
Implicit teardown uses standard RSVP message processing. Per standard Implicit teardown uses standard RSVP message processing. Per standard
RSVP processing, a S2L sub-LSP may be removed from a P2MP TE LSP by RSVP processing, an S2L sub-LSP may be removed from a P2MP TE LSP by
sending a modified message for the Path or Resv message that sending a modified message for the Path or Resv message that
previously advertised the S2L sub-LSP. This message MUST list all S2L previously advertised the S2L sub-LSP. This message MUST list all S2L
sub-LSPs that are not being removed. When using this approach, a node sub-LSPs that are not being removed. When using this approach, a node
processing a message that removes a S2L sub-LSP from a P2MP TE LSP processing a message that removes an S2L sub-LSP from a P2MP TE LSP
MUST ensure that the S2L sub-LSP is not included in any other Path MUST ensure that the S2L sub-LSP is not included in any other Path
state associated with session before interrupting the data path to state associated with session before interrupting the data path to
that egress. All other message processing remains unchanged. that egress. All other message processing remains unchanged.
When implicit teardown is used to delete one or more S2L sub-LSPs, by When implicit teardown is used to delete one or more S2L sub-LSPs, by
modifying a Path message, a transit LSR may have to generate a modifying a Path message, a transit LSR may have to generate a
PathTear message downstream to delete one or more of these S2L sub- PathTear message downstream to delete one or more of these S2L sub-
LSPs. This can happen if as a result of the implicit deletion of S2L LSPs. This can happen if as a result of the implicit deletion of S2L
sub-LSP(s) there are no remaining S2L sub-LSPs to send in the sub-LSP(s) there are no remaining S2L sub-LSPs to send in the
corresponding Path message downstream. corresponding Path message downstream.
skipping to change at page 21, line 25 skipping to change at page 22, line 18
for the corresponding Path message. The PathTear message is signaled for the corresponding Path message. The PathTear message is signaled
with the SESSION and SENDER_TEMPLATE objects corresponding to the with the SESSION and SENDER_TEMPLATE objects corresponding to the
P2MP LSP and the <Sub-Group Originator ID, Sub-Group ID> tuple P2MP LSP and the <Sub-Group Originator ID, Sub-Group ID> tuple
corresponding to the Path message. This approach SHOULD be used when corresponding to the Path message. This approach SHOULD be used when
all the egresses signaled by a Path message need to be removed from all the egresses signaled by a Path message need to be removed from
the P2MP LSP. Other S2L sub-LSPs, from other sub-groups signaled the P2MP LSP. Other S2L sub-LSPs, from other sub-groups signaled
using other Path messages, are not affected by the PathTear. using other Path messages, are not affected by the PathTear.
A transit LSR that propagates the PathTear message downstream MUST A transit LSR that propagates the PathTear message downstream MUST
ensure that it sets the <Sub-Group Originator ID, Sub-Group ID> tuple ensure that it sets the <Sub-Group Originator ID, Sub-Group ID> tuple
in the PathTear message to the values used to generate the previous in the PathTear message to the values used in the Path message used
Path message that corresponds to the S2L sub-LSPs being deleted by it to set up the S2L sub-LSPs being torn down. The transit LSR may need
in the PathTear message. The transit LSR may need to generate to generate multiple PathTear messages for an incoming PathTear
multiple PathTear messages for an incoming PathTear message if it had message if it had performed transit fragmentation for the
performed transit fragmentation for the corresponding incoming Path corresponding incoming Path message.
message.
When a P2MP LSP is removed by the ingress, a PathTear message MUST be When a P2MP LSP is removed by the ingress, a PathTear message MUST be
generated for each Path message used to signal the P2MP LSP. generated for each Path message used to signal the P2MP LSP.
8. Notify and ResvConf Messages 8. Notify and ResvConf Messages
8.1. Notify Messages 8.1. Notify Messages
The Notify Request object and Notify messages are described in The Notify Request object and Notify message are described in
[RFC3473]. Both object and messages SHALL be supported for delivery [RFC3473]. Both object and message SHALL be supported for delivery of
of upstream and downstream notification. Processing not detailed in upstream and downstream notification. Processing not detailed in this
this section MUST comply to [RFC3473]. section MUST comply to [RFC3473].
1. Upstream Notification 1. Upstream Notification
If a transit LSR sets the Sub-Group Originator ID in the If a transit LSR sets the Sub-Group Originator ID in the
SENDER_TEMPLATE object of a Path message to its own address and the SENDER_TEMPLATE object of a Path message to its own address and the
incoming Path message carries a Notify Request object then this LSR incoming Path message carries a Notify Request object then this LSR
MUST change the Notify node address in the Notify Request object to MUST change the Notify node address in the Notify Request object to
its own address in the Path message that it sends. its own address in the Path message that it sends.
If this LSR subsequently receives a corresponding Notify message from If this LSR subsequently receives a corresponding Notify message from
skipping to change at page 22, line 23 skipping to change at page 23, line 14
field values in the original Path message received from upstream. field values in the original Path message received from upstream.
The receiver of an (upstream) Notify message MUST identify the state The receiver of an (upstream) Notify message MUST identify the state
referenced in this message based on the SESSION and SENDER_TEMPLATE. referenced in this message based on the SESSION and SENDER_TEMPLATE.
2. Downstream Notification 2. Downstream Notification
A transit LSR sets the Sub-Group Originator ID in the FILTER_SPEC A transit LSR sets the Sub-Group Originator ID in the FILTER_SPEC
object(s) of a Resv message to the value, that was received in the object(s) of a Resv message to the value, that was received in the
corresponding Path message. If the incoming Resv message carries a corresponding Path message. If the incoming Resv message carries a
Notify Request object then the LSR MUST set the Notify node address Notify Request object then:
in the Notify Request object to the value, that was received in the
corresponding Path message, in the Resv message that it sends - If there is at least another incoming Resv message that carries a
upstream. Notify Request object and the LSR merges these Resv messages into a
single Resv message that is sent upstream, the LSR MUST set the
Notify node address in the Notify Request object to its Router ID.
- Else if the LSR sets the Sub-Group Originator ID in the outgoing
Path message, that corresponds to the received Resv message, to its
own address, the LSR MUST set the Notify node address in the Notify
Request object to its Router ID.
- Else the LSR MUST propagate the Notify Request object unchanged, in
the Resv message that it sends upstream.
If this LSR subsequently receives a corresponding Notify message from If this LSR subsequently receives a corresponding Notify message from
an upstream LSR than it MUST: an upstream LSR then it MUST:
- send a Notify message downstream toward the Notify
node address that the LSR received in the Resv message.
- process the sub-group fields of the FILTER_SPEC object in the - process the sub-group fields of the FILTER_SPEC object in the
received Notify message, and modify their values in the Notify received Notify message, and modify their values in the Notify
message that is forwarded to match the sub-group field values message that is forwarded to match the sub-group field values
in the original Path message sent downstream by this LSR. in the original Path message sent downstream by this LSR.
- send a Notify message downstream toward the Notify
node address that the LSR received in the Resv message.
The receiver of a (downstream) Notify message MUST identify the state The receiver of a (downstream) Notify message MUST identify the state
referenced in the message based on the SESSION and FILTER_SPEC referenced in the message based on the SESSION and FILTER_SPEC
objects. objects.
The consequence of these rules for a P2MP LSP is that an upstream The consequence of these rules for a P2MP LSP is that an upstream
Notify message generated on a branch will result in a Notify being Notify message generated on a branch will result in a Notify being
delivered to the upstream Notify node address. The receiver of the delivered to the upstream Notify node address. The receiver of the
Notify message MUST NOT assume that the Notify message applies to all Notify message MUST NOT assume that the Notify message applies to all
downstream egresses, but MUST examine the information in the message downstream egresses, but MUST examine the information in the message
to determine to which egresses the message applies. to determine to which egresses the message applies.
Downstream Notify messages MUST be replicated at branch LSRs Downstream Notify messages MUST be replicated at branch LSRs
according to the Notify Request objects received on Resv messages. according to the Notify Request objects received on Resv messages.
Some downstream branches might not request Notify messages, but all Some downstream branches might not request Notify messages, but all
that have requested Notify messages MUST receive them that have requested Notify messages MUST receive them.
8.2. ResvConf Messages 8.2. ResvConf Messages
ResvConf messages are described in [RFC2205]. ResvConf processing in ResvConf messages are described in [RFC2205]. ResvConf processing in
[RFC3473] and [RFC3209] is taken directly from [RFC2205]. An egress [RFC3473] and [RFC3209] is taken directly from [RFC2205]. An egress-
LSR may include a RESV_CONFIRM object that contains the egress LSR's LSR MAY include a RESV_CONFIRM object that contains the egress-LSR's
address. The object and message SHALL be supported for the address. The object and message SHALL be supported for the
confirmation of receipt of the Resv message in P2MP TE LSPs. confirmation of receipt of the Resv message in P2MP TE LSPs.
Processing not detailed in this section MUST comply to [RFC2205]. Processing not detailed in this section MUST comply to [RFC2205].
A transit LSR sets the Sub-Group Originator ID in the FILTER_SPEC A transit LSR sets the Sub-Group Originator ID in the FILTER_SPEC
object(s) of a Resv message to the value, that was received in the object(s) of a Resv message to the value, that was received in the
corresponding Path message. If any of the incoming Resv messages corresponding Path message. If any of the incoming Resv messages
corresponding to a single Path message carry a RESV_CONFIRM object corresponding to a single Path message carry a RESV_CONFIRM object
then the LSR MUST include a RESV_CONFIRM object in the corresponding then the LSR MUST include a RESV_CONFIRM object in the corresponding
Resv message that it sends upstream and MUST set the receiver address Resv message that it sends upstream. If the sub-group originator ID
in the RESV_CONFIRM object to the value that was received in the is its own address then it MUST set the receiver address in the
corresponding Resv message. RESV_CONFIRM object to this addresse, else it MUST propagate the
object unchanged.
A transit LSR sets the Sub-Group Originator ID in the FILTER_SPEC
object(s) of a Resv message to the value that was received in the
corresponding Path message. If an incoming Resv message corresponding
to a single Path message carries a RESV_CONFIRM object then the LSR
MUST include a RESV_CONFIRM object in the corresponding Resv message
that it sends upstream and:
- If there is at least another incoming Resv message that carries a
RESV_CONFIRM object and the LSR merges these Resv messages into a
single Resv message that is sent upstream, the LSR MUST set the
receiver address in the RESV_CONFIRM object to its Router ID.
- If the LSR sets the Sub-Group Originator ID in the outgoing Path
message, that corresponds to the received Resv message, to its own
address, the LSR MUST set the receiver address in the RESV_CONFIRM
object to its Router ID.
- Else the LSR MUST propagate the RESV_CONFIRM object unchanged, in
the Resv message that it sends upstream.
If this LSR subsequently receives a corresponding ResvConf message If this LSR subsequently receives a corresponding ResvConf message
from an upstream LSR than it MUST: from an upstream LSR than it MUST:
- send a ResvConf message downstream toward the receiver address that
the LSR received in the RESV_CONFIRM object in the Resv message.
- process the sub-group fields of the FILTER_SPEC object in the - process the sub-group fields of the FILTER_SPEC object in the
received ResvConf message, and modify their values in the ResvConf received ResvConf message, and modify their values in the ResvConf
message that is forwarded to match the sub-group field values message that is forwarded to match the sub-group field values
in the original Path message sent downstream by this LSR. in the original Path message sent downstream by this LSR.
- send a ResvConf message downstream toward the receiver address that
the LSR received in the RESV_CONFIRM object in the Resv message.
The receiver of a ResvConf message MUST identify the state referenced The receiver of a ResvConf message MUST identify the state referenced
in this message based on the SESSION and FILTER_SPEC objects. in this message based on the SESSION and FILTER_SPEC objects.
The consequence of these rules for a P2MP LSP is that a ResvConf The consequence of these rules for a P2MP LSP is that a ResvConf
message generated at the ingress will result in a ResvConf message message generated at the ingress will result in a ResvConf message
being delivered to the branch and then to the receiver address in the being delivered to the branch and then to the receiver address in the
original RESV_CONFIRM object. The receiver of a ResvConf message MUST original RESV_CONFIRM object. The receiver of a ResvConf message MUST
NOT assume that the ResvConf message should be sent to all downstream NOT assume that the ResvConf message should be sent to all downstream
egresses, but MUST replicate the message according to the egresses, but MUST replicate the message according to the
RESV_CONFIRM objects received in Resv messages. Some downstream RESV_CONFIRM objects received in Resv messages. Some downstream
branches might not request ResvConf messages, and ResvConf messages branches might not request ResvConf messages, and ResvConf messages
SHOULD NOT be sent on these branches. All downstream branches that do SHOULD NOT be sent on these branches. All downstream branches that
requested ResvConf messages MUST be sent such a message. requested ResvConf messages MUST be sent such a message.
9. Refresh Reduction 9. Refresh Reduction
The refresh reduction procedures described in [RFC2961] are equally The refresh reduction procedures described in [RFC2961] are equally
applicable to P2MP LSP described in this document. Refresh reduction applicable to P2MP LSPs described in this document. Refresh reduction
applies to individual messages and the state they install/maintain, applies to individual messages and the state they install/maintain,
and that continues to be the case for P2MP LSP. and that continues to be the case for P2MP LSPs.
10. State Management 10. State Management
State signaled by a P2MP Path message is managed by a local State signaled by a P2MP Path message is identified by a local
implementation using the <P2MP ID, Tunnel ID, Extended Tunnel ID> as implementation using the <P2MP ID, Tunnel ID, Extended Tunnel ID> as
part of the SESSION object and <Tunnel Sender Address, LSP ID, Sub- part of the SESSION object and <Tunnel Sender Address, LSP ID, Sub-
Group Originator ID, Sub-Group ID> as part of the SENDER_TEMPLATE Group Originator ID, Sub-Group ID> as part of the SENDER_TEMPLATE
object. object.
Additional information signaled in the Path/Resv message is part of Additional information signaled in the Path/Resv message is part of
the state created by a local implementation. This includes PHOP/NHOP the state created by a local implementation. This includes PHOP/NHOP
and SENDER_TSPEC/FILTER_SPEC object. and SENDER_TSPEC/FILTER_SPEC objects.
10.1. Incremental State Update 10.1. Incremental State Update
RSVP as defined in [RFC2205] and as extended by RSVP-TE [RFC3209] and RSVP as defined in [RFC2205] and as extended by RSVP-TE [RFC3209] and
GMPLS [RFC3473] uses the same basic approach to state communication GMPLS [RFC3473] uses the same basic approach to state communication
and synchronization, namely full state is sent in each state and synchronization, namely full state is sent in each state
advertisement message. Per [RFC2205] Path and Resv messages are advertisement message. Per [RFC2205] Path and Resv messages are
idempotent. Also, [RFC2961] categorizes RSVP messages into two types: idempotent. Also, [RFC2961] categorizes RSVP messages into two types:
trigger and refresh messages and improves RSVP message handling and trigger and refresh messages and improves RSVP message handling and
scaling of state refreshes but does not modify the full state scaling of state refreshes but does not modify the full state
skipping to change at page 24, line 47 skipping to change at page 26, line 18
case, there is the message overhead of sending the full state and the case, there is the message overhead of sending the full state and the
cost of processing it. It is desirable to overcome this drawback and cost of processing it. It is desirable to overcome this drawback and
add/delete S2L sub-LSPs to a P2MP LSP by incrementally updating the add/delete S2L sub-LSPs to a P2MP LSP by incrementally updating the
existing state. existing state.
It is possible to use the procedures described in this document to It is possible to use the procedures described in this document to
allow S2L sub-LSPs to be incrementally added or deleted from the P2MP allow S2L sub-LSPs to be incrementally added or deleted from the P2MP
LSP by allowing a Path or a PathTear message to incrementally change LSP by allowing a Path or a PathTear message to incrementally change
the existing P2MP LSP Path state. the existing P2MP LSP Path state.
As described in section 4.2, multiple Path messages can be used to As described in section 5.2, multiple Path messages can be used to
signal a P2MP LSP. The Path messages are distinguished by different signal a P2MP LSP. The Path messages are distinguished by different
<Sub-Group Originator ID, sub-Group ID> tuples in the SENDER_TEMPLATE <Sub-Group Originator ID, Sub-Group ID> tuples in the SENDER_TEMPLATE
object. In order to perform incremental S2L sub-LSP state addition a object. In order to perform incremental S2L sub-LSP state addition a
separate Path message with a new sub-Group ID is used to add the new separate Path message with a new Sub-Group ID is used to add the new
S2L sub-LSPs, by the ingress LSR. The Sub-Group Originator ID MUST be S2L sub-LSPs, by the ingress-LSR. The Sub-Group Originator ID MUST be
set to the TE Router ID [RFC3477] of the node that sets the Sub-Group set to the TE Router ID [RFC3477] of the node that sets the Sub-Group
ID. ID.
This maintains the idempotent nature of RSVP Path messages; avoids This maintains the idempotent nature of RSVP Path messages; avoids
keeping track of individual S2L sub-LSP state expiration and provides keeping track of individual S2L sub-LSP state expiration and provides
the ability to perform incremental P2MP LSP state updates. the ability to perform incremental P2MP LSP state updates.
10.2. Combining Multiple Path Messages 10.2. Combining Multiple Path Messages
There is a tradeoff between the number of Path messages used by the There is a tradeoff between the number of Path messages used by the
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It is possible to combine S2L sub-LSPs previously advertised in It is possible to combine S2L sub-LSPs previously advertised in
different Path messages in a single Path message in order to reduce different Path messages in a single Path message in order to reduce
the number of Path messages needed to maintain the P2MP LSP. This can the number of Path messages needed to maintain the P2MP LSP. This can
also be done by a transit node that performed fragmentation and at a also be done by a transit node that performed fragmentation and at a
later point is able to combine multiple Path messages that it later point is able to combine multiple Path messages that it
generated into a single Path message. This may happen when one or generated into a single Path message. This may happen when one or
more S2L sub-LSPs are pruned from the existing Path states. more S2L sub-LSPs are pruned from the existing Path states.
The new Path message is signaled by the node that is combining The new Path message is signaled by the node that is combining
multiple Path messages with all the S2L sub-LSPs that are being multiple Path messages with all the S2L sub-LSPs that are being
combined in a single Path message. This Path message MAY contain a combined in a single Path message. This Path message MAY contain new
new Sub-Group ID field value. When a new Path and Resv message that Sub-Group ID field values. When a new Path and Resv message that is
is signaled for an existing S2L sub-LSP is received by a transit LSR, signaled for an existing S2L sub-LSP is received by a transit LSR,
state including the new instance of the S2L sub-LSP is created. state including the new instance of the S2L sub-LSP is created.
The S2L sub-LSP SHOULD continue to be advertised in both the old and The S2L sub-LSP SHOULD continue to be advertised in both the old and
new Path messages until a Resv message listing the S2L sub-LSP and new Path messages until a Resv message listing the S2L sub-LSP and
corresponding to the new Path message is received by the combining corresponding to the new Path message is received by the combining
node. Hence until this point state for the S2L sub-LSP SHOULD be node. Hence until this point state for the S2L sub-LSP SHOULD be
maintained as part of the Path state for both the old and the new maintained as part of the Path state for both the old and the new
Path message [Section 3.1.3, RFC2205]. At that point the S2L sub-LSP Path message [Section 3.1.3, RFC2205]. At that point the S2L sub-LSP
SHOULD be deleted from the old Path state using the procedures of SHOULD be deleted from the old Path state using the procedures of
section 7. section 7.
A Path message with a sub-Group_ID(n) may signal a set of S2L sub- A Path message with a Sub-Group_ID(n) may signal a set of S2L sub-
LSPs that belong partially or entirely to an already existing Sub- LSPs that belong partially or entirely to an already existing Sub-
Group_ID(i), the SESSION object and <Sender Tunnel Address, LSP-ID, Group_ID(i), the SESSION object and <Sender Tunnel Address, LSP-ID,
Sub-Group Originator ID> being the same. Or it may signal a strictly Sub-Group Originator ID> being the same. Or it may signal a strictly
non-overlapping new set of S2L sub-LSPs with a strictly higher sub- non-overlapping new set of S2L sub-LSPs with a strictly higher Sub-
Group_ID value. Group_ID value.
1) If sub-Group_ID(i) = sub-Group_ID(n), then either a full refresh 1) If Sub-Group_ID(i) = Sub-Group_ID(n), then either a full refresh
is indicated by the Path message or a S2L Sub-LSP is added to/deleted is indicated by the Path message or an S2L Sub-LSP is added
from the group signaled by sub-Group_ID(n) to/deleted from the group signaled by Sub-Group_ID(n)
2) If sub-Group_ID(i) != sub-Group_ID(n), then the Path message is 2) If Sub-Group_ID(i) != Sub-Group_ID(n), then the Path message is
signaling a set of S2L sub-LSPs that belong partially or entirely to signaling a set of S2L sub-LSPs that belong partially or entirely to
an already existing Sub-Group_ID(i) or a strictly non-overlapping set an already existing Sub-Group_ID(i) or a strictly non-overlapping set
of S2L sub-LSPs. of S2L sub-LSPs.
11. Error Processing 11. Error Processing
PathErr and ResvErr messages are processed as per RSVP-TE procedures. PathErr and ResvErr messages are processed as per RSVP-TE procedures.
Note that an LSR on receiving a PathErr/ResvErr message for a Note that an LSR on receiving a PathErr/ResvErr message for a
particular S2L sub-LSP changes the state only for that S2L sub-LSP. particular S2L sub-LSP changes the state only for that S2L sub-LSP.
Hence other S2L sub-LSPs are not impacted. If the ingress node Hence other S2L sub-LSPs are not impacted. If the ingress node
requests the maintenance of the 'LSP integrity', any error reported requests 'LSP integrity', an error reported on a branch of a P2MP TE
within the P2MP TE LSP must be reported to (at least) any other LSP for a particular S2L sub-LSP may change the state of any other
branching nodes belonging to this LSP. Therefore, reception of an S2L sub-LSP of the same P2MP TE LSP. This is explained further in
error message for a particular S2L sub-LSP MAY change the state of section 11.3
any other S2L sub- LSP of the same P2MP TE LSP.
11.1. PathErr Messages 11.1. PathErr Messages
The PathErr message will include one or more <S2L_SUB_LSP> objects. The PathErr message will include one or more S2L_SUB_LSP objects. The
The resulting modified format for a PathErr message is: resulting modified format for a PathErr message is:
<PathErr Message> ::= <Common Header> [ <INTEGRITY> ] <PathErr Message> ::= <Common Header> [ <INTEGRITY> ]
[ [<MESSAGE_ID_ACK> | [ [<MESSAGE_ID_ACK> |
<MESSAGE_ID_NACK>] ... ] <MESSAGE_ID_NACK>] ... ]
[ <MESSAGE_ID> ] [ <MESSAGE_ID> ]
<SESSION> <ERROR_SPEC> <SESSION> <ERROR_SPEC>
[ <ACCEPTABLE_LABEL_SET> ... ] [ <ACCEPTABLE_LABEL_SET> ... ]
[ <POLICY_DATA> ... ] [ <POLICY_DATA> ... ]
<sender descriptor> <sender descriptor>
[ <S2L sub-LSP descriptor list> ] [ <S2L sub-LSP descriptor list> ]
PathErr messages generation is unmodified, but nodes that set the PathErr messages generation is unmodified, but nodes that set the
Sub-Group Originator field and propagate a received PathErr message Sub-Group Originator field and propagate a received PathErr message
upstream MUST replace the Sub-Group fields received in the PathErr upstream MUST replace the Sub-Group fields received in the PathErr
message with the value that was received in the Sub-Group fields of message with the value that was received in the Sub-Group fields of
the Path message from the upstream neighbor. Note the receiver of a the Path message from the upstream neighbor. Note the receiver of a
PathErr message is able to identify the errored outgoing Path PathErr message is able to identify the errored outgoing Path
message, and outgoing interface, based on the Sub-Group fields message, and outgoing interface, based on the Sub-Group fields
received in the PathErr message. received in the PathErr message. The S2L sub-LSP descriptor list is
defined in section 5.1.
11.2. ResvErr Messages 11.2. ResvErr Messages
The ResvErr message will include one or more <S2L_SUB_LSP> objects. The ResvErr message will include one or more S2L_SUB_LSP objects. The
The resulting modified format for a ResvErr Message is: resulting modified format for a ResvErr Message is:
<ResvErr Message> ::= <Common Header> [ <INTEGRITY> ] <ResvErr Message> ::= <Common Header> [ <INTEGRITY> ]
[ [<MESSAGE_ID_ACK> | [ [<MESSAGE_ID_ACK> |
<MESSAGE_ID_NACK>] ... ] <MESSAGE_ID_NACK>] ... ]
[ <MESSAGE_ID> ] [ <MESSAGE_ID> ]
<SESSION> <RSVP_HOP> <SESSION> <RSVP_HOP>
<ERROR_SPEC> [ <SCOPE> ] <ERROR_SPEC> [ <SCOPE> ]
[ <ACCEPTABLE_LABEL_SET> ... ] [ <ACCEPTABLE_LABEL_SET> ... ]
[ <POLICY_DATA> ... ] [ <POLICY_DATA> ... ]
<STYLE> <flow descriptor list> <STYLE> <flow descriptor list>
ResvErr messages generation is unmodified, but nodes that set the ResvErr messages generation is unmodified, but nodes that set the
Sub-Group Originator field and propagate a received ResvErr message Sub-Group Originator field and propagate a received ResvErr message
downstream MUST replace the Sub-Group fields received in the ResvErr downstream MUST replace the Sub-Group fields received in the ResvErr
message with the value that was set in the Sub-Group fields of the message with the value that was set in the Sub-Group fields of the
Path message sent to the downstream neighbor. Note the receiver of a Path message sent to the downstream neighbor. Note the receiver of a
ResvErr message is able to identify the errored outgoing Path ResvErr message is able to identify the errored outgoing Resv
message, and outgoing interface, based on the Sub-Group fields message, and outgoing interface, based on the Sub-Group fields
received in the ResvErr message. received in the ResvErr message. The flow descriptor list is defined
in section 6.1.
11.3. Branch Failure Handling 11.3. Branch Failure Handling
During setup and during normal operation, PathErr messages may be During setup and during normal operation, PathErr messages may be
received at a branch node. In all cases, a received PathErr message received at a branch node. In all cases, a received PathErr message
is first processed per standard processing rules. That is: the is first processed per standard processing rules. That is: the
PathErr message is sent hop-by-hop to the ingress/branch LSR for that PathErr message is sent hop-by-hop to the ingress/branch LSR for that
Path message. Intermediate nodes until this ingress/branch LSR MAY Path message. Intermediate nodes until this ingress/branch LSR MAY
inspect this message but take no action upon it. The behavior of a inspect this message but take no action upon it. The behavior of a
branch LSR that generates a PathErr message is under the control of branch LSR that generates a PathErr message is under the control of
the ingress LSR. the ingress-LSR.
The default behavior is that the PathErr message does not have the The default behavior is that the PathErr message does not have the
Path_State_Removed flag set. However, if the ingress LSR has set the Path_State_Removed flag set. However, if the ingress-LSR has set the
LSP integrity flag on the Path message (see LSP_REQUIRED_ATTRIBUTEs LSP integrity flag on the Path message (see LSP_REQUIRED_ATTRIBUTEs
object in section 5.2.4) and if the Path_State_Removed flag is object in section 5.2.4) and if the Path_State_Removed flag is
supported, the LSR generating a PathErr to report the failure of a supported, the LSR generating a PathErr to report the failure of a
branch of the P2MP LSP SHOULD set the Path_State_Removed flag. branch of the P2MP LSP SHOULD set the Path_State_Removed flag.
A branch LSR that receives a PathErr message with the A branch LSR that receives a PathErr message during LSP setup with
Path_State_Removed flag set MUST act according to the wishes of the the Path_State_Removed flag set MUST act according to the wishes of
ingress LSR. The default behavior is that the branch LSR clears the the ingress-LSR. The default behavior is that the branch LSR clears
Path_State_Removed flag on the PathErr and sends it further upstream. the Path_State_Removed flag on the PathErr and sends it further
It does not tear any other branches of the LSP. However, if the LSP upstream. It does not tear any other branches of the LSP. However,
integrity flag is set on the Path message, the branch LSR MUST send if the LSP integrity flag is set on the Path message, the branch LSR
PathTear on all other downstream branches and send the PathErr MUST send PathTear on all other downstream branches and send the
message upstream with the Path_State_Removed flag set. PathErr message upstream with the Path_State_Removed flag set.
A branch LSR that receives a PathErr message with the A branch LSR that receives a PathErr message with the
Path_State_Removed flag clear MUST act according to the wishes of the Path_State_Removed flag clear MUST act according to the wishes of the
ingress LSR. The default behavior is that the branch LSR forwards the ingress-LSR. The default behavior is that the branch LSR forwards the
PathErr upstream and takes no further action. However, if the LSP PathErr upstream and takes no further action. However, if the LSP
integrity flag is set on the Path message, the branch LSR MUST send integrity flag is set on the Path message, the branch LSR MUST send
PathTear on all downstream branches and send the PathErr upstream PathTear on all downstream branches and send the PathErr upstream
with the Path_State_Removed flag set (per [RFC3473]). with the Path_State_Removed flag set (per [RFC3473]).
In all cases, the PathErr message forwarded by a branch LSR MUST In all cases, the PathErr message forwarded by a branch LSR MUST
contain the S2L sub-LSP identification and explicit routes of all contain the S2L sub-LSP identification and explicit routes of all
branches that are reported by received PathErr messages and all branches that are reported by received PathErr messages and all
branches that are explicitly torn by the branch LSR. branches that are explicitly torn by the branch LSR.
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Downstream nodes process the change in the ADMIN_STATUS object per Downstream nodes process the change in the ADMIN_STATUS object per
[RFC3473], including generation of Resv messages. When the last [RFC3473], including generation of Resv messages. When the last
received upstream ADMIN_STATUS object had the R bit set, branch nodes received upstream ADMIN_STATUS object had the R bit set, branch nodes
wait for a Resv message with a matching ADMIN_STATUS object to be wait for a Resv message with a matching ADMIN_STATUS object to be
received (or a corresponding PathErr or ResvTear messsage) on all received (or a corresponding PathErr or ResvTear messsage) on all
branches before relaying a corresponding Resv message upstream. branches before relaying a corresponding Resv message upstream.
13. Label Allocation on LANs with Multiple Downstream Nodes 13. Label Allocation on LANs with Multiple Downstream Nodes
A sender on a LAN uses a different label for sending traffic to each A branch LSR of a P2MP LSP on an Ethernet LAN segment SHOULD send one
node on the LAN that belongs to the P2MP LSP. Thus the sender copy of the data traffic per downstream LSR connected on that LAN for
performs replication. It may be considered desirable on a LAN to use that P2MP LSP. Procedures for preventing MPLS labelled traffic
the same label for sending traffic to multiple nodes belonging to the replication in such a case is beyond the scope of this document.
same P2MP LSP, to avoid replication. Procedures for doing this are
for further study.
14. P2MP LSP and Sub-LSP Re-optimization 14. P2MP LSP and Sub-LSP Re-optimization
It is possible to change the path used by P2MP LSPs to reach the It is possible to change the path used by P2MP LSPs to reach the
destinations of the P2MP Tunnel. There are two methods that can be destinations of the P2MP Tunnel. There are two methods that can be
used to accomplish this. The first is make-before-break, defined in used to accomplish this. The first is make-before-break, defined in
[RFC3209], and the second uses the sub-groups defined above. [RFC3209], and the second uses the sub-groups defined above.
14.1. Make-before-break 14.1. Make-before-break
skipping to change at page 29, line 27 skipping to change at page 31, line 8
signaled with a different LSP ID, corresponding to the new P2MP LSP. signaled with a different LSP ID, corresponding to the new P2MP LSP.
After moving traffic to the new P2MP LSP, the ingress can tear down After moving traffic to the new P2MP LSP, the ingress can tear down
the old P2MP LSP. This procedure can be used to re-optimize the path the old P2MP LSP. This procedure can be used to re-optimize the path
of the entire P2MP LSP or paths to a subset of the destinations of of the entire P2MP LSP or paths to a subset of the destinations of
the P2MP LSP. When modifying just a portion of the P2MP LSP this the P2MP LSP. When modifying just a portion of the P2MP LSP this
approach requires the entire P2MP LSP to be resignaled. approach requires the entire P2MP LSP to be resignaled.
14.2. Sub-Group Based Re-optimization 14.2. Sub-Group Based Re-optimization
Any node may initiate re-optimization of a set of S2L sub-LSPs by Any node may initiate re-optimization of a set of S2L sub-LSPs by
using the incremental state update and then, optionally, combining using incremental state update and then, optionally, combining
multiple path messages. multiple path messages.
To alter the path taken by a particular set of S2L sub-LSPs the node To alter the path taken by a particular set of S2L sub-LSPs the node
initiating the path change initiates one or more separate Path initiating the path change initiates one or more separate Path
messages, for the same P2MP LSP, each with a new sub-Group ID. The messages, for the same P2MP LSP, each with a new sub-Group ID. The
generation of these Path messages, each with one or more S2L sub- generation of these Path messages, each with one or more S2L sub-
LSPs, follows procedures in section 5.2. As is the case in Section LSPs, follows procedures in section 5.2. As is the case in Section
10.2, a particular egress continues to be advertised in both the old 10.2, a particular egress continues to be advertised in both the old
and new Path messages until a Resv message listing the egress and and new Path messages until a Resv message listing the egress and
corresponding to the new Path message is received by the re- corresponding to the new Path message is received by the re-
optimizing node. At that point the egress SHOULD be deleted from the optimizing node. At that point the egress SHOULD be deleted from the
old Path state using the procedures of section 7. Sub-tree re- old Path state using the procedures of section 7. Sub-tree re-
optimization is then completed. optimization is then completed.
Sub-Group based re-optimization may result in transient data
duplication as the new Path messages for a set of S2L sub-LSPs may
transit one or more nodes with the old Path state for the same set of
S2L sub-LSPs.
As is always the case, a node may choose to combine multiple path As is always the case, a node may choose to combine multiple path
messages as described in section 10.2. messages as described in section 10.2.
15. Fast Reroute 15. Fast Reroute
[RFC4090] extensions can be used to perform fast reroute for the [RFC4090] extensions can be used to perform fast reroute for the
mechanism described in this document. This section uses terminology mechanism described in this document when applied within packet
defined in [RFC4090] and fast reroute procedures defined in [RFC4090] networks. GMPLS introduces other protection techniques that can be
MUST be followed unless specified below. The head-end and transit applied to packet and non-packet environments [RECOVERY], but which
LSRs MUST follow the SESSION_ATTRIBUTE and FAST_REROUTE object are not discussed further in this document. This section only applies
processing as specified in [RFC4090] for each Path message and S2L to LSRs that support [RFC4090].
sub-LSP of a P2MP LSP. Each S2L sub-LSP of a P2MP LSP MUST have the
same protection characteristics. The RRO processing MUST apply to This section uses terminology defined in [RFC4090] and fast reroute
SRRO as well unless modified below. procedures defined in [RFC4090] MUST be followed unless specified
below. The head-end and transit LSRs MUST follow the
SESSION_ATTRIBUTE and FAST_REROUTE object processing as specified in
[RFC4090] for each Path message and S2L sub-LSP of a P2MP LSP. Each
S2L sub-LSP of a P2MP LSP MUST have the same protection
characteristics. The RRO processing MUST apply to SRRO as well unless
modified below.
The sections that follow describe how Fast Reroute may be applied to
P2MP MPLS TE LSPs in all of the principal operational scenarios. This
document does not describe the detailed processing steps for every
imaginable usage case and they may be described in future documents,
as needed.
15.1. Facility Backup 15.1. Facility Backup
Facility backup can be used for link or node protection of LSRs on Facility backup can be used for link or node protection of LSRs on
the path of a P2MP LSP. The downstream labels MUST be learned by the the path of a P2MP LSP. The downstream labels MUST be learned by the
PLR as specified in [RFC4090] from the label corresponding to the S2L PLR as specified in [RFC4090] from the label corresponding to the S2L
sub-LSP in the RESV message. SERO processing for SEROs signaled in a sub-LSP in the RESV message. SERO processing for SEROs signaled in a
backup tunnel MUST follow backup tunnel ERO processing described in backup tunnel MUST follow backup tunnel ERO processing described in
[RFC4090]. [RFC4090].
15.1.1. Link Protection 15.1.1. Link Protection
If link protection is desired, a bypass tunnel MUST be used to If link protection is desired, a bypass tunnel MUST be used to
protect the link between the PLR and next-hop. Thus all S2L sub-LSPs protect the link between the PLR and next-hop. Thus all S2L sub-LSPs
that use the link MUST be protected in the event of link failure. that use the link SHOULD be protected in the event of link failure.
Note that all such S2L sub-LSPs belonging to a particular instance of Note that all such S2L sub-LSPs belonging to a particular instance of
a P2MP tunnel will share the same outgoing label on the link between a P2MP tunnel SHOULD share the same outgoing label on the link
the PLR and the next-hop. This is the P2MP LSP label on the link. between the PLR and the next-hop as per section 5.2.1. This is the
Label stacking is used to send data for each P2MP LSP into the bypass P2MP LSP label on the link. Label stacking is used to send data for
tunnel. The inner label is the P2MP LSP label allocated by the next- each P2MP LSP into the bypass tunnel. The inner label is the P2MP LSP
hop. During failure Path messages for each S2L sub-LSP, that are label allocated by the next-hop.
effected, MUST be sent to the MP, by the PLR. It is recommended that
the PLR use the sender template specific method to identify these During failure, Path messages for each S2L sub-LSP that is affected,
Path messages. Hence the PLR will set the source address in the MUST be sent to the MP, by the PLR. It is RECOMMENDED that the PLR
sender template to a local PLR address. The MP MUST use the LSP-ID to uses the sender template-specific method to identify these Path
identify the corresponding S2L sub-LSPs. The MP MUST not use the messages. Hence the PLR will set the source address in the sender
<sub-group originator ID, sub-group ID> while identifying the template to a local PLR address.
corresponding S2L sub-LSPs. In order to further process a S2L sub-LSP
the MP MUST determine the protected S2L sub-LSP using the LSP-id and The MP MUST use the LSP-ID to identify the corresponding S2L sub-
the <S2L_SUB_LSP> object. LSPs. The MP MUST NOT use the <sub-group originator ID, sub-group
ID> while identifying the corresponding S2L sub-LSPs. In order to
further process an S2L sub-LSP the MP MUST determine the protected
S2L sub-LSP using the LSP-id and the S2L_SUB_LSP object.
15.1.2. Node Protection 15.1.2. Node Protection
If node protection is desired the PLR MUST use one or more P2P bypass If node protection is desired the PLR SHOULD use one or more P2P
tunnels to protect the set of S2L sub-LSPs that transit the protected bypass tunnels to protect the set of S2L sub-LSPs that transit the
node. Each of these P2P bypass tunnels MUST intersect the path of the protected node. Each of these P2P bypass tunnels MUST intersect the
S2L sub-LSPs that they protect on a LSR that is downstream from the path of the S2L sub-LSPs that they protect on an LSR that is
protected node. This constrains the set of S2L sub-LSPs being backed downstream from the protected node. This constrains the set of S2L
up via that bypass tunnel to those S2L sub-LSPs that pass through a sub-LSPs being backed- up via that bypass tunnel to those S2L sub-
common downstream MP. This MP is the destination of the bypass LSPs that pass through a common downstream MP. This MP is the
tunnel. The MP MUST allocate the same label to all such S2L sub-LSPs destination of the bypass tunnel. When the PLR forwards incoming data
belonging to a particular P2MP LSP. This is the inner label used for a P2MP LSP into the bypass tunnel, the outer label is the bypass
during label stacking by the PLR when it sends data for each P2MP LSP tunnel label and the inner label is the label allocated by the MP to
into the bypass tunnel. The outer label is the bypass tunnel label. the set of S2L sub-LSPs belonging to that P2MP LSP.
After detecting failure of the protected node the PLR MUST send a After detecting failure of the protected node the PLR MUST send one
Path message for each protected S2L sub-LSP to the MP of the or more Path messages for all protected S2L sub-LSPs to the MP of the
protected S2L sub-LSP. It is recommended that the PLR use the sender protected S2L sub-LSP. It is RECOMMENDED that the PLR use the sender
template specific method to identify these Path messages. Hence the template specific method to identify these Path messages. Hence the
PLR will set the source address in the sender template to a local PLR PLR will set the source address in the sender template to a local PLR
address. The MP MUST use the LSP-ID to identify the corresponding S2L address. The MP MUST use the LSP-ID to identify the corresponding S2L
sub-LSPs. The MP MUST not use the <sub-group originator ID, sub-group sub-LSPs. The MP MUST NOT use the <sub-group originator ID, sub-group
ID> while identifying the corresponding S2L sub-LSPs. In order to ID> while identifying the corresponding S2L sub-LSPs because the sub-
further process a S2L sub-LSP the MP MUST determine the protected S2L group originator ID might be changed by some LSR that is bypassed by
sub-LSP using the LSP-id and the <S2L_SUB_LSP> object. the bypass tunnel. In order to further process an S2L sub-LSP the MP
MUST determine the protected S2L sub-LSP using the LSP-ID and the
S2L_SUB_LSP object.
Note that node protection MAY require the PLR to be branch capable in Note that node protection MAY require the PLR to be branch capable in
the data plane as multiple bypass tunnels may be required to backup the data plane as multiple bypass tunnels may be required to backup
the set of S2L sub-LSPs passing through the protected node. If the the set of S2L sub-LSPs passing through the protected node. If the
PLR is not branch capable, the node protection mechanism described PLR is not branch capable, the node protection mechanism described
here is applicable to only those cases where all the S2L sub-LSPs here is applicable to only those cases where all the S2L sub-LSPs
passing through the protected node also pass through a single MP that passing through the protected node also pass through a single MP that
is downstream from the protected node. Procedures for node protection is downstream from the protected node. A PLR MUST set the Node
when a PLR is not branch capable and all the protected S2L sub-LSPs protection flag in the RRO/SRRO as specified in [RFC4090]. If a PLR
do not pass through a single MP that is downstream from the protected is not branch capable and one or more S2L sub-LSPs are added to a
node are for further study. It is also to be noted that procedures in P2MP tree and these S2L sub-LSPs do not transit the existing MP
this section require P2P bypass tunnels. Procedures for using P2MP downstream of the protected node, then the PLR MUST reset this flag.
bypass tunnels are for further study.
15.2. One to One Backup It is to be noted that procedures in this section require P2P bypass
tunnels. Procedures for using P2MP bypass tunnels are for further
study.
One to one backup as described in [RFC4090] can be used to protect a 15.2. one-to-one Backup
one-to-one backup as described in [RFC4090] can be used to protect a
particular S2L sub-LSP against link and next-hop failure. Protection particular S2L sub-LSP against link and next-hop failure. Protection
may be used for one or more S2L sub-LSPs between the PLR and the may be used for one or more S2L sub-LSPs between the PLR and the
next-hop. All the S2L sub-LSPs corresponding to the same instance of next-hop. All the S2L sub-LSPs corresponding to the same instance of
the P2MP tunnel, between the PLR and the next-hop share the same P2MP the P2MP tunnel, between the PLR and the next-hop SHOULD share the
LSP label. same P2MP LSP label as per section 5.2.1. All such S2L sub-LSPs
belonging to a P2MP LSP MUST be protected.
All or some of these S2L sub-LSPs may be protected.
The detour S2L sub-LSPs may or may not share labels, depending on the The backup S2L sub-LSPs may traverse different next-hops at the PLR.
detour path. Thus the set of outgoing labels and next-hops for a P2MP Thus the set of outgoing labels and next-hops for a P2MP LSP that was
LSP that was using a single next-hop and label between the PLR and using a single next-hop and label between the PLR and next-hop before
next-hop before protection, may change once protection is triggerred. protection, may change once protection is triggerred. This MAY
require a PLR to be branch capable in the data plane. If the PLR is
not branch capable, the one-to-one backup mechanisms described here
are only applicable to those cases where all the backup S2L sub-LSPs
pass through the same next-hop downstream of the PLR. Procedures for
one-to-one backup when a PLR is not branch capable and all the backup
S2L sub-LSPs do not pass through the same downstream next-hop are for
further study.
Its is recommended that the path specific method be used to identify It is recommended that the path specific method be used to identify a
a backup S2L sub-LSP. Hence the DETOUR object SHOULD be inserted in backup S2L sub-LSP. Hence the DETOUR object SHOULD be inserted in the
the backup Path message. A backup S2L sub-LSP MUST be treated as backup Path message. A backup S2L sub-LSP MUST be treated as
belonging to a different P2MP tunnel instance than the one specified belonging to a different P2MP tunnel instance than the one specified
by the LSP-id. Furthermore multiple backup S2L sub-LSPs MUST be by the LSP-id. Furthermore multiple backup S2L sub-LSPs MUST be
treated as part of the same P2MP tunnel instance if they have the treated as part of the same P2MP tunnel instance if they have the
same LSP-id and the same DETOUR objects. Note that as specified in same LSP-ID and the same DETOUR objects. Note that as specified in
section 4 S2L sub-LSPs between different P2MP tunnel instances use section 4 S2L sub-LSPs between different P2MP tunnel instances use
different labels. different labels.
If there is only one S2L sub-LSP in the Path message, the DETOUR If there is only one S2L sub-LSP in the Path message, the DETOUR
object applies to that sub-LSP. If there are multiple S2L sub-LSPs in object applies to that sub-LSP. If there are multiple S2L sub-LSPs in
the Path message the DETOUR applies to all the S2L sub-LSPs. the Path message the DETOUR object applies to all the S2L sub-LSPs.
16. Support for LSRs that are not P2MP Capable 16. Support for LSRs that are not P2MP Capable
It may be that some LSRs in a network are capable of processing the It may be that some LSRs in a network are capable of processing the
P2MP extensions described in this document, but do not support P2MP P2MP extensions described in this document, but do not support P2MP
branching in the data plane. If such an LSR is requested to become a branching in the data plane. If such an LSR is requested to become a
branch LSR by a received Path message, it MUST respond with a PathErr branch LSR by a received Path message, it MUST respond with a PathErr
message carrying the Error Code "Routing Error" and Error Value message carrying the Error Code "Routing Error" and Error Value
"Unable to Branch". "Unable to Branch".
Its also conceivable that some LSRs, in a network deploying P2MP It is also conceivable that some LSRs, in a network deploying P2MP
capability, may not support the extensions described in this capability, may not support the extensions described in this
document. If a Path message for the establishment of a P2MP LSP document. If a Path message for the establishment of a P2MP LSP
reaches such an LSR it will reject it with a PathErr because it will reaches such an LSR it will reject it with a PathErr because it will
not recognize the C-Type of the P2MP SESSION object. not recognize the C-Type of the P2MP SESSION object.
LSRs that do not support the P2MP extensions in this document may be LSRs that do not support the P2MP extensions in this document may be
included as transit LSRs by the use of LSP-stitching [LSP-STITCH] and included as transit LSRs by the use of LSP-stitching [LSP-STITCH] and
LSP-hierarchy [RFC4206]. Note that LSRs that are required to play any LSP-hierarchy [RFC4206]. Note that LSRs that are required to play any
other role in the network (ingress, branch or egress) MUST support other role in the network (ingress, branch or egress) MUST support
the extensions defined in this document. the extensions defined in this document.
skipping to change at page 33, line 18 skipping to change at page 35, line 19
only need to process data belonging to the P2P LSP segment. Hence only need to process data belonging to the P2P LSP segment. Hence
these transit LSRs do not need to support P2MP MPLS. This P2P LSP these transit LSRs do not need to support P2MP MPLS. This P2P LSP
segment is stitched to the incoming P2MP LSP. After the P2P LSP segment is stitched to the incoming P2MP LSP. After the P2P LSP
segment is established the P2MP Path message is sent to the next P2MP segment is established the P2MP Path message is sent to the next P2MP
capable LSR as a directed Path message. The next P2MP capable LSR capable LSR as a directed Path message. The next P2MP capable LSR
stitches the P2P LSP segment to the outgoing P2MP LSP. stitches the P2P LSP segment to the outgoing P2MP LSP.
In packet networks, the S2L sub-LSPs may be nested inside the outer In packet networks, the S2L sub-LSPs may be nested inside the outer
P2P LSP. Hence label stacking can be used to enable use of the same P2P LSP. Hence label stacking can be used to enable use of the same
LSP segment for multiple P2MP LSP. Stitching and nesting LSP segment for multiple P2MP LSP. Stitching and nesting
considerations and procedures are described further in [INT-REG]. considerations and procedures are described further in [LSP-STITCH]
and [RFC4206].
It may be an overhead for an operator to configure the P2P LSP It may be an overhead for an operator to configure the P2P LSP
segments in advance, when it is desired to support legacy LSRs. It segments in advance, when it is desired to support legacy LSRs. It
may be desirable to do this dynamically. The ingress can use IGP may be desirable to do this dynamically. The ingress can use IGP
extensions to determine non P2MP capable LSRs [TE-NODE-CAP]. It can extensions to determine P2MP capable LSRs [TE-NODE-CAP]. It can use
use this information to compute S2L sub-LSP paths such that they this information to compute S2L sub-LSP paths such that they avoid
avoid these legacy LSRs. The explicit route object of a S2L sub-LSP legacy non-P2MP capable LSRs. The explicit route object of an S2L
path may contain loose hops if there are legacy LSRs along the path. sub-LSP path may contain loose hops if there are legacy LSRs along
The corresponding explicit route contains a list of objects upto the the path. The corresponding explicit route contains a list of objects
P2MP capable LSR that is adjacent to a legacy LSR followed by a loose upto the P2MP capable LSR that is adjacent to a legacy LSR followed
object with the address of the next P2MP capable LSR. The P2MP by a loose object with the address of the next P2MP capable LSR. The
capable LSR expands the loose hop using its TED. When doing this it P2MP capable LSR expands the loose hop using its TED. When doing this
determines that the loose hop expansion requires a P2P LSP to tunnel it determines that the loose hop expansion requires a P2P LSP to
through the legacy LSR. If such a P2P LSP exists, it uses that P2P tunnel through the legacy LSR. If such a P2P LSP exists, it uses that
LSP. Else it establishes the P2P LSP. The P2MP Path message is sent P2P LSP. Else it establishes the P2P LSP. The P2MP Path message is
to the next P2MP capable LSR using non-adjacent signaling. The P2MP sent to the next P2MP capable LSR using non-adjacent signaling.
capable LSR that initiates the non-adjacent signaling message to the
next P2MP capable LSR may have to employ a fast detection mechanism
such as [BFD] [BFD-MPLS] to the next P2MP capable LSR.
This may be needed for the directed Path message Head-End to use node The P2MP capable LSR that initiates the non-adjacent signaling
protection FRR when the protected node is the directed Path message message to the next P2MP capable LSR may have to employ a fast
tail. detection mechanism such as [BFD] [BFD-MPLS] to the next P2MP capable
LSR. This may be needed for the directed Path message Head-End to
use node protection FRR when the protected node is the directed Path
message tail.
Note that legacy LSRs along a P2P LSP segment cannot perform node Note that legacy LSRs along a P2P LSP segment cannot perform node
protection of the tail of the P2P LSP segment. protection of the tail of the P2P LSP segment.
17. Reduction in Control Plane Processing with LSP Hierarchy 17. Reduction in Control Plane Processing with LSP Hierarchy
It is possible to take advantage of LSP hierarchy [RFC4206] while It is possible to take advantage of LSP hierarchy [RFC4206] while
setting up P2MP LSP, as described in the previous section, to reduce setting up P2MP LSP, as described in the previous section, to reduce
control plane processing along transit LSRs that are P2MP capable. control plane processing along transit LSRs that are P2MP capable.
This is applicable only in environments where LSP hierarchy can be This is applicable only in environments where LSP hierarchy can be
used. Transit LSRs along a P2P LSP segment, being used by a P2MP LSP, used. Transit LSRs along a P2P LSP segment, being used by a P2MP LSP,
do not process control plane messages associated with the P2MP LSP. do not process control plane messages associated with the P2MP LSP.
Infact they are not aware of these messages as they are tunneled over In fact they are not aware of these messages as they are tunneled
the P2P LSP segment. This reduces the amount of control plane over the P2P LSP segment. This reduces the amount of control plane
processing required on these transit LSRs. processing required on these transit LSRs.
Note that the P2P LSPs be dynamically setup as described in the Note that the P2P LSPs can be set up dynamically as described in the
previous section or preconfigured. For example in Figure 2, PE1 can previous section or preconfigured. For example in Figure 2 in section
setup a P2P LSP to P1 and use that as a LSP segment. The Path 24, PE1 can setup a P2P LSP to P1 and use that as a LSP segment. The
messages for PE3 and PE4 can now be tunneled over the LSP segment. Path messages for PE3 and PE4 can now be tunneled over the LSP
Thus P3 is not aware of the P2MP LSP and does not process the P2MP segment. Thus P3 is not aware of the P2MP LSP and does not process
control messages. the P2MP control messages.
18. P2MP LSP Remerging and Cross-Over 18. P2MP LSP Remerging and Cross-Over
This section is currently under discussion between the authors and
will be updated in the next revision.
This section details the procedures for detecting and dealing with This section details the procedures for detecting and dealing with
re-merge and cross-over. The term re-merge refers to the case of an re-merge and cross-over. The term re-merge refers to the case of an
ingress or transit node that creates a branch of a P2MP LSP, a re- ingress or transit node that creates a branch of a P2MP LSP, a re-
merge branch, which intersects the P2MP LSP at another node farther merge branch, which intersects the P2MP LSP at another node farther
down the tree. This may occur due to such events as an error in path down the tree. This may occur due to such events as an error in path
calculation, an error in manual configuration, or network topology calculation, an error in manual configuration, or network topology
changes during the establishment of the P2MP LSP. If the procedures changes during the establishment of the P2MP LSP. If the procedures
detailed in this section are not followed, data duplication will detailed in this section are not followed, data duplication will
result. result.
skipping to change at page 34, line 50 skipping to change at page 36, line 47
that creates a branch of a P2MP LSP, a cross-over branch, which that creates a branch of a P2MP LSP, a cross-over branch, which
intersects the P2MP LSP at another node farther down the tree. It is intersects the P2MP LSP at another node farther down the tree. It is
unlike re-merge in that at the intersecting node the cross-over unlike re-merge in that at the intersecting node the cross-over
branch has a different outgoing interface as well as a different branch has a different outgoing interface as well as a different
incoming interface. This may be necessary in certain combinations of incoming interface. This may be necessary in certain combinations of
topology and technology; e.g., in a transparent optical network in topology and technology; e.g., in a transparent optical network in
which different wavelengths are required to reach different leaf which different wavelengths are required to reach different leaf
nodes. nodes.
Normally, a P2MP LSP has a single incoming interface on which all of Normally, a P2MP LSP has a single incoming interface on which all of
the Path messages associated with that P2MP LSP are received. The the data for the P2MP LSP is received. The incoming interface is
incoming interface is identified by the IF_ID RSVP_HOP Object, if identified by the IF_ID RSVP_HOP Object, if present, and by interface
present, and by interface over which the Path message was received if over which the Path message was received if the IF_ID RSVP_HOP Object
the IF_ID RSVP_HOP Object is not present. However, in the case of is not present. However, in the case of dynamic LSP re-routing, the
dynamic LSP re-routing, the incoming interface may change. incoming interface may change.
Similarly, in both the re-merge case and cross-over cases, a node Similarly, in both the re-merge case and cross-over cases, a node
will receive a Path message for a given P2MP LSP on a different will receive a Path message for a given P2MP LSP identifying a
incoming interface, and the node needs to be able to distinguish different incoming interface for the data, and the node needs to be
between dynamic LSP re-routing and the re-merge/cross-over cases. able to distinguish between dynamic LSP re-routing and the re-
merge/cross-over cases.
(Make-before-break represents yet another similar but different case, Make-before-break represents yet another similar but different case,
in that the incoming interface associated with the make-before-break in that the incoming interface associated with the make-before-break
P2MP LSP may be different than that associated with the original P2MP P2MP LSP may be different than that associated with the original P2MP
LSP. However, the two P2MP LSPs will be treated as distinct, but LSP. However, the two P2MP LSPs will be treated as distinct, but
related, LSPs because they will have different LSP ID field values in related, LSPs because they will have different LSP ID field values in
their SENDER_TEMPLATE objects.) their SENDER_TEMPLATE objects.
18.1. Procedures 18.1. Procedures
When a node receives a Path message, it MUST check whether it has When a node receives a Path message, it MUST check whether it has
matching state for the P2MP LSP. Matching state is identified by matching state for the P2MP LSP. Matching state is identified by
comparing the SESSION and SENDER_TEMPLATE objects in the received comparing the SESSION and SENDER_TEMPLATE objects in the received
Path message with the SESSION and SENDER_TEMPLATE objects of each Path message with the SESSION and SENDER_TEMPLATE objects of each
locally maintained P2MP LSP Path state. The P2MP ID, Tunnel ID, and locally maintained P2MP LSP Path state. The P2MP ID, Tunnel ID, and
Extended Tunnel ID in the SESSION Object and the sender address and Extended Tunnel ID in the SESSION Object and the sender address and
LSP ID in the SENDER_TEMPLATE object are used for the comparison. If LSP ID in the SENDER_TEMPLATE object are used for the comparison. If
the node has matching state and the incoming interface for the the node has matching state and the incoming interface for the
received Path message is different than the incoming interface of the received Path message is different than the incoming interface of the
matching P2MP LSP Path state, then the node MUST determine whether it matching P2MP LSP Path state, then the node MUST determine whether it
is dealing with dynamic LSP rerouting or re-merge/cross-over. is dealing with dynamic LSP rerouting or re-merge/cross-over.
Dynamic LSP rerouting is identified by checking whether there is any Dynamic LSP rerouting is identified by checking whether there is any
intersection between the set of SUB-LSP objects associated with the intersection between the set of S2L_SUB_LSP objects associated with
matching P2MP LSP Path state and the set of SUB-LSP objects in the the matching P2MP LSP Path state and the set of S2L_SUB_LSP objects
received Path message. If there is any intersection, then dynamic in the received Path message. If there is any intersection, then
re-routing has occurred. If there is no intersection between the two dynamic re-routing has occurred. If there is no intersection between
sets of SUB-LSP objects, then either re-merge or cross-over has the two sets of S2L_SUB_LSP objects, then either re-merge or cross-
occurred. (Note that in the case of dynamic LSP rerouting, Path over has occurred. (Note that in the case of dynamic LSP rerouting,
messages for the non-intersecting members of set of SUB-LSPs Path messages for the non-intersecting members of set of S2L_SUB_LSPs
associated with the matching P2MP LSP Path state will be received associated with the matching P2MP LSP Path state will be received
subsequently on the new incoming interface.) subsequently on the new incoming interface.)
In order to identify the re-merge case, the node processing the In order to identify the re-merge case, the node processing the
received Path message MUST identify the outgoing interfaces received Path message MUST identify the outgoing interfaces
associated with the matching P2MP Path state. Re-merge has occurred associated with the matching P2MP Path state. Re-merge has occurred
if there is any intersection between the set of outgoing interfaces if there is any intersection between the set of outgoing interfaces
associated with the matching P2MP LSP Path state and the set of associated with the matching P2MP LSP Path state and the set of
outgoing interfaces in the received Path message. outgoing interfaces in the received Path message.
18.1.1. Re-Merge Procedures 18.1.1. Re-Merge Procedures
There are two approaches to dealing with re-merge case. In the There are two approaches to dealing with the re-merge case. In the
first, the node detecting the re-merge case, i.e., the re-merge node, first, the node detecting the re-merge case, i.e., the re-merge node,
allows the re-merge case to persist but data from all but one allows the re-merge case to persist but data from all but one
incoming interface is dropped at the re-merge node. In the second, incoming interface is dropped at the re-merge node. In the second,
the re-merge node initiates the removal of the re-merge branch(es) the re-merge node initiates the removal of the re-merge branch(es)
via signaling. Which approach is used is a matter of local policy. via signaling. Which approach is used is a matter of local policy. A
A node MUST support both approaches and MUST allow user configuration node MUST support both approaches and MUST allow user configuration
of which approach is to be used. of which approach is to be used.
When configured to allow a re-merge case to persist, the re-merge When configured to allow a re-merge case to persist, the re-merge
node MUST validate consistency between the objects included the node MUST validate consistency between the objects included in the
received Path message and the matching P2MP LSP Path state. Any received Path message and the matching P2MP LSP Path state. Any
inconsistencies MUST result in an appropriate PathErr message sent to inconsistencies MUST result in an PathErr message sent to the
the previous hop of the received Path message. The Error Code is set previous hop of the received Path message. The Error Code is set to
to "Routing Problem" and the Error Value is set to "P2MP Re-Merge "Routing Problem" and the Error Value is set to "P2MP Re-Merge
Parameter Mistmatch". Parameter Mistmatch".
If there are no inconsistencies, the node logically merges, from the If there are no inconsistencies, the node logically merges, from the
downstream perspective, the control state of incoming Path message downstream perspective, the control state of incoming Path message
with the matching P2MP LSP Path state. Specifically, procedures with the matching P2MP LSP Path state. Specifically, procedures
related to processing of messages received from upstream MUST NOT be related to processing of messages received from upstream MUST NOT be
modified from the upstream perspective; this includes refresh and modified from the upstream perspective; this includes refresh and
state timeout related processing. In addition to the standard state timeout related processing. In addition to the standard
upstream related procedures, the node MUST ensure that each object upstream related procedures, the node MUST ensure that each object
received from upstream is appropriately represented within the set of received from upstream is appropriately represented within the set of
Path messages sent downstream. For example, the received <S2L sub-LSP Path messages sent downstream. For example, the received <S2L sub-LSP
descriptor list> MUST be included in the set of outgoing Path descriptor list> MUST be included in the set of outgoing Path
messages. If there are any NOTIFY_REQUEST request objects present, messages. If there are any NOTIFY_REQUEST objects present, then the
then the procedures defined in Section 8 MUST be followed for both procedures defined in Section 8 MUST be followed for all Path and
Path and Resv messages. Special processing is also required for Resv Resv messages. Special processing is also required for Resv
processing. Specifically, any Resv message received from downstream processing. Specifically, any Resv message received from downstream
MUST be mapped into an outgoing Resv message that is sent to the MUST be mapped into an outgoing Resv message that is sent to the
previous hop of the received Path message. In practice, this previous hop of the received Path message. In practice, this
translates to decomposing the complete <S2L sub-LSP descriptor list> translates to decomposing the complete <S2L sub-LSP descriptor list>
into sub-sets that match the incoming Path messages and then into sub-sets that match the incoming Path messages and then
constructing an outgoing Resv message for each incoming Path message. constructing an outgoing Resv message for each incoming Path message.
When configured to allow a re-merge case to persist, the re-merge When configured to allow a re-merge case to persist, the re-merge
node receives data associated with the P2MP LSP on multiple incoming node receives data associated with the P2MP LSP on multiple incoming
interfaces, but it may only send the data from one of these interfaces, but it MUST only send the data from one of these
interfaces to its outgoing interfaces, i.e., the node MUST drop data interfaces to its outgoing interfaces, i.e., the node MUST drop data
from all but one incoming interface. This ensures that duplicate from all but one incoming interface. This ensures that duplicate
data is not sent on any outgoing interface. The mechanism used to data is not sent on any outgoing interface. The mechanism used to
select the incoming interface to use is implementation specific and select the incoming interface to use is implementation specific and
is outside the scope of this document. is outside the scope of this document.
When configured to correct the re-merge branch via signaling, the re- When configured to correct the re-merge branch via signaling, the re-
merge node MUST send a PathErr message corresponding to the received merge node MUST send a PathErr message corresponding to the received
Path message. The PathErr message MUST include all of the objects Path message. The PathErr message MUST include all of the objects
normally included in a PathErr message, as well as one or more SUB- normally included in a PathErr message, as well as one or more
LSP objects from the set of sub-LSPs associated with the matching S2L_SUB_LSP objects from the set of sub-LSPs associated with the
P2MP LSP Path state. A minimum of three SUB-LSP objects is matching P2MP LSP Path state. A minimum of three S2L_SUB_LSP objects
RECOMMENDED. This will allow the node that caused the re-merge to is RECOMMENDED. This will allow the node that caused the re-merge to
identify the outgoing Path state associated with the valid portion of identify the outgoing Path state associated with the valid portion of
the P2MP LSP. The set of SUB-LSP objects in the received Path message the P2MP LSP. The set of S2L_SUB_LSP objects in the received Path
MUST also be included. The PathErr message MUST include the Error message MUST also be included. The PathErr message MUST include the
Code "Routing Problem" and Error Value of "P2MP Remerge Detected". Error Code "Routing Problem" and Error Value of "P2MP Remerge
The node MAY set the Path_State_Removed flag [RFC3473]. As is always Detected". The node MAY set the Path_State_Removed flag [RFC3473].
the case, the PathErr message is sent to the previous hop of the As is always the case, the PathErr message is sent to the previous
received Path message. hop of the received Path message.
A node that receives a PathErr message that contains the Error Value A node that receives a PathErr message that contains the Error Value
"Routing Problem/P2MP Remerge Detected" MUST determine if it is the "Routing Problem/P2MP Remerge Detected" MUST determine if it is the
node that created the re-merge case. This is done by checking node that created the re-merge case. This is done by checking
whether there is any intersection between the set of SUB-LSP objects whether there is any intersection between the set of S2L_SUB_LSP
associated with the matching P2MP LSP Path state and the set of SUB- objects associated with the matching P2MP LSP Path state and the set
LSP objects in the received PathErr message. If there is, then the of other-branch S2L_SUB_LSP objects in the received PathErr message.
node created the re-merge case. If there is, then the node created the re-merge case. Other-branch
S2L_SUB_LSP objects are those S2L_SUB_LSP objects included, by the
node detecting the re-merge case, in the PathErr message that were
taken from the matching P2MP LSP Path state. Such S2L_SUB_LSP
objects are identifiable as they will not be included in the Path
message associated with the received PathErr message. See Section
11.1 for more details on how such an association is identified.
The node SHOULD remove the re-merge case by moving the SUB-LSP The node SHOULD remove the re-merge case by moving the S2L_SUB_LSP
objects included in the Path message associated with the received objects included in the Path message associated with the received
PathErr message to the outgoing interface associated with the PathErr message to the outgoing interface associated with the
matching P2MP LSP Path state. A trigger Path message for the moved matching P2MP LSP Path state. A trigger Path message for the moved
SUB-LSP objects is then sent via that outgoing interface. If the S2L_SUB_LSP objects is then sent via that outgoing interface. If the
received PathErr message did not have the Path_State_Removed flag received PathErr message did not have the Path_State_Removed flag
set, the node SHOULD send a PathTear via the outgoing interface set, the node SHOULD send a PathTear via the outgoing interface
associated with the re-merge branch. associated with the re-merge branch.
If use of a new outgoing interface violates one or more SERO If use of a new outgoing interface violates one or more SERO
constraint, then a PathErr message containing the associated egresses constraint, then a PathErr message containing the associated egresses
and any identified SUB-LSP objects SHOULD be generated with the Error and any identified S2L_SUB_LSP objects SHOULD be generated with the
Code "Routing Problem" and Error Value of "ERO Resulted in Remerge". Error Code "Routing Problem" and Error Value of "ERO Resulted in
Remerge".
The only case where this process will fail is when all the listed The only case where this process will fail is when all the listed
SUB-LSP objects are deleted prior to the PathErr message propagating S2L_SUB_LSP objects are deleted prior to the PathErr message
to the ingress. In this case, the whole process will be corrected on propagating to the ingress. In this case, the whole process will be
the next (refresh or trigger) transmission of the offending Path corrected on the next (refresh or trigger) transmission of the
message. offending Path message.
19. New and Updated Message Objects 19. New and Updated Message Objects
This section presents the RSVP object formats as modified by this This section presents the RSVP object formats as modified by this
document. document.
19.1. SESSION Object 19.1. SESSION Object
A P2MP LSP SESSION object is used. This object uses the existing A P2MP LSP SESSION object is used. This object uses the existing
SESSION C-Num. New C-Types are defined to accommodate a logical P2MP SESSION C-Num. New C-Types are defined to accommodate a logical P2MP
destination identifier of the P2MP Tunnel. This SESSION object has a destination identifier of the P2MP Tunnel. This SESSION object has a
similar structure as the existing point to point RSVP-TE SESSION similar structure as the existing point to point RSVP-TE SESSION
object. However the destination address is set to the P2MP ID object. However the destination address is set to the P2MP ID
instead of the unicast Tunnel Endpoint address. All S2L sub-LSPs that instead of the unicast Tunnel Endpoint address. All S2L sub-LSPs that
are part of the same P2MP LSP share the same SESSION object. This are part of the same P2MP LSP share the same SESSION object. This
SESSION object identifies the P2MP Tunnel. SESSION object identifies the P2MP Tunnel.
The combination of the SESSION object, the SENDER_TEMPLATE object and The combination of the SESSION object, the SENDER_TEMPLATE object and
the <S2L_SUB_LSP> object, identifies each S2L sub-LSP. This follows the S2L_SUB_LSP object, identifies each S2L sub-LSP. This follows the
the existing P2P RSVP-TE notion of using the SESSION object for existing P2P RSVP-TE notion of using the SESSION object for
identifying a P2P Tunnel which in turn can contain multiple LSPs, identifying a P2P Tunnel which in turn can contain multiple LSPs,
each distinguished by a unique SENDER_TEMPLATE object. each distinguished by a unique SENDER_TEMPLATE object.
19.1.1. P2MP LSP Tunnel IPv4 SESSION Object 19.1.1. P2MP LSP Tunnel IPv4 SESSION Object
Class = SESSION, P2MP_LSP_TUNNEL_IPv4 C-Type = 13 Class = SESSION, P2MP_LSP_TUNNEL_IPv4 C-Type = 13
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 38, line 45 skipping to change at page 40, line 46
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MUST be zero | Tunnel ID | | MUST be zero | Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID | | Extended Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
P2MP ID P2MP ID
A 32-bit identifier used in the SESSION object that remains A 32-bit identifier used in the SESSION object that remains
constant over the life of the P2MP tunnel. It encodes the constant over the life of the P2MP tunnel. It encodes the
P2MP ID and identifies the set of destinations of the P2MP P2MP Identifier that is unique within the scope of the Ingress
Tunnel. LSR.
Tunnel ID Tunnel ID
A 16-bit identifier used in the SESSION object that remains A 16-bit identifier used in the SESSION object that remains
constant over the life of the P2MP tunnel. constant over the life of the P2MP tunnel.
Extended Tunnel ID Extended Tunnel ID
A 32-bit identifier used in the SESSION object that remains A 32-bit identifier used in the SESSION object that remains
constant over the life of the P2MP tunnel. Normally set to constant over the life of the P2MP tunnel. Ingress LSRs
all zeros. Ingress nodes that wish to narrow the scope of a that wish to have a globally unique identifier for the P2MP tunnel
SESSION to the ingress-PID pair may place their IPv4 address SHOULD place their tunnel sender address here. A combination of
here as a globally unique identifier [RFC3209]. this address, P2MP ID and Tunnel ID provides a globally unique
identifier for the P2MP tunnel.
19.1.2. P2MP LSP Tunnel IPv6 SESSION Object 19.1.2. P2MP LSP Tunnel IPv6 SESSION Object
This is same as the P2MP IPv4 LSP SESSION Object with the difference This is same as the P2MP IPv4 LSP SESSION Object with the difference
that the extended tunnel ID may be set to a 16 byte identifier that the extended tunnel ID may be set to a 16 byte identifier
[RFC3209]. [RFC3209].
Class = SESSION, P2MP_LSP_TUNNEL_IPv4 C-Type = 14 Class = SESSION, P2MP_LSP_TUNNEL_IPv4 C-Type = 14
0 1 2 3 0 1 2 3
skipping to change at page 39, line 38 skipping to change at page 41, line 42
| MUST be zero | Tunnel ID | | MUST be zero | Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Tunnel ID (16 bytes) | | Extended Tunnel ID (16 bytes) |
| | | |
| ....... | | ....... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
19.2. SENDER_TEMPLATE object 19.2. SENDER_TEMPLATE object
The SENDER_TEMPLATE object contains the ingress-LSR source address. The SENDER_TEMPLATE object contains the ingress-LSR source address.
LSP ID can be can be changed to allow a sender to share resources The LSP ID can be changed to allow a sender to share resources with
with itself. Thus multiple instances of the P2MP tunnel can be itself. Thus multiple instances of the P2MP tunnel can be created,
created, each with a different LSP ID. The instances can share each with a different LSP ID. The instances can share resources with
resources with each other, but use different labels. The S2L sub-LSPs each other. The S2L sub-LSPs corresponding to a particular instance
corresponding to a particular instance use the same LSP ID. use the same LSP ID.
As described in section 4.2 it is necessary to distinguish different As described in section 4.2 it is necessary to distinguish different
Path messages that are used to signal state for the same P2MP LSP by Path messages that are used to signal state for the same P2MP LSP by
using a <Sub-Group ID Originator ID, Sub-Group ID> tuple. The using a <Sub-Group ID Originator ID, Sub-Group ID> tuple. The
SENDER_TEMPLATE object is modified to carry this information as shown SENDER_TEMPLATE object is modified to carry this information as shown
below. below.
19.2.1. P2MP LSP Tunnel IPv4 SENDER_TEMPLATE Object 19.2.1. P2MP LSP Tunnel IPv4 SENDER_TEMPLATE Object
Class = SENDER_TEMPLATE, P2MP_LSP_TUNNEL_IPv4 C-Type = 12 Class = SENDER_TEMPLATE, P2MP_LSP_TUNNEL_IPv4 C-Type = 12
skipping to change at page 40, line 22 skipping to change at page 42, line 25
| IPv4 tunnel sender address | | IPv4 tunnel sender address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | LSP ID | | Reserved | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Group Originator ID | | Sub-Group Originator ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Sub-Group ID | | Reserved | Sub-Group ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv4 tunnel sender address IPv4 tunnel sender address
See [RFC3209] See [RFC3209].
Sub-Group Originator ID Sub-Group Originator ID
The Sub-Group Originator ID is set to the TE Router ID of The Sub-Group Originator ID is set to the TE Router ID of
the LSR that originates the Path message. This is either the the LSR that originates the Path message. This is either the
ingress LSR or a LSR which re-originates the Path message ingress-LSR or an LSR which re-originates the Path message
with its own Sub-Group Originator ID. with its own Sub-Group Originator ID.
Sub-Group ID Sub-Group ID
An identifier of a Path message used to differentiate An identifier of a Path message used to differentiate
multiple Path messages that signal state for the same P2MP multiple Path messages that signal state for the same P2MP
LSP. This may be seen as identifying a group of one or more LSP. This may be seen as identifying a group of one or more
egress nodes targeted by this Path message. egress nodes targeted by this Path message.
LSP ID LSP ID
See [RFC3209] See [RFC3209]
skipping to change at page 41, line 22 skipping to change at page 43, line 27
| Sub-Group Originator ID | | Sub-Group Originator ID |
+ + + +
| (16 bytes) | | (16 bytes) |
+ + + +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Sub-Group ID | | Reserved | Sub-Group ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 tunnel sender address IPv6 tunnel sender address
See [RFC3209] See [RFC3209].
Sub-Group Originator ID Sub-Group Originator ID
The Sub-Group Originator ID is set to the IPv6 TE Router ID The Sub-Group Originator ID is set to the IPv6 TE Router ID
of the LSR that originates the Path message. This is either of the LSR that originates the Path message. This is either
the ingress LSR or a LSR which re-originates the Path the ingress-LSR or an LSR which re-originates the Path
message with its own Sub-Group Originator ID. message with its own Sub-Group Originator ID.
Sub-Group ID Sub-Group ID
As above in section 19.2.1. As above in section 19.2.1.
LSP ID LSP ID
See [RFC3209] See [RFC3209]
19.3. <S2L_SUB_LSP> Object 19.3. S2L_SUB_LSP Object
A new <S2L_SUB_LSP> object identifies a particular S2L sub-LSP A S2L_SUB_LSP object identifies a particular S2L sub-LSP belonging to
belonging to the P2MP LSP. the P2MP LSP.
19.3.1. <S2L_SUB_LSP> IPv4 Object 19.3.1. S2L_SUB_LSP IPv4 Object
SUB_LSP Class = 50, S2L_SUB_LSP_IPv4 C-Type = 1 S2L_SUB_LSP Class = 50, S2L_SUB_LSP_IPv4 C-Type = 1
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 S2L Sub-LSP destination address | | IPv4 S2L Sub-LSP destination address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv4 Sub-LSP destination address IPv4 Sub-LSP destination address
IPv4 address of the S2L sub-LSP destination. IPv4 address of the S2L sub-LSP destination.
19.3.2. <S2L_SUB_LSP> IPv6 Object 19.3.2. S2L_SUB_LSP IPv6 Object
SUB_LSP Class = 50, S2L_SUB_LSP_IPv6 C-Type = 2 S2L_SUB_LSP Class = 50, S2L_SUB_LSP_IPv6 C-Type = 2
This is same as the S2L IPv4 Sub-LSP object, with the difference that This is same as the S2L IPv4 Sub-LSP object, with the difference that
the destination address is a 16 byte IPv6 address. the destination address is a 16 byte IPv6 address.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 S2L Sub-LSP destination address (16 bytes) | | IPv6 S2L Sub-LSP destination address (16 bytes) |
| .... | | .... |
| | | |
skipping to change at page 42, line 37 skipping to change at page 45, line 5
The FILTER_SPEC object is canonical to the P2MP SENDER_TEMPLATE The FILTER_SPEC object is canonical to the P2MP SENDER_TEMPLATE
object. object.
19.4.1. P2MP LSP_IPv4 FILTER_SPEC Object 19.4.1. P2MP LSP_IPv4 FILTER_SPEC Object
Class = FILTER SPEC, P2MP LSP_IPv4 C-Type = 12 Class = FILTER SPEC, P2MP LSP_IPv4 C-Type = 12
The format of the P2MP LSP_IPv4 FILTER_SPEC object is identical to The format of the P2MP LSP_IPv4 FILTER_SPEC object is identical to
the P2MP LSP_IPv4 SENDER_TEMPLATE object. the P2MP LSP_IPv4 SENDER_TEMPLATE object.
19.4.2. P2MP LSP_IPv4 FILTER_SPEC Object 19.4.2. P2MP LSP_IPv6 FILTER_SPEC Object
Class = FILTER SPEC, P2MP LSP_IPv6 C-Type = 13 Class = FILTER SPEC, P2MP LSP_IPv6 C-Type = 13
The format of the P2MP LSP_IPv6 FILTER_SPEC object is identical to The format of the P2MP LSP_IPv6 FILTER_SPEC object is identical to
the P2MP LSP_IPv6 SENDER_TEMPLATE object. the P2MP LSP_IPv6 SENDER_TEMPLATE object.
19.5. P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO) 19.5. P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO)
The P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO) is defined as The P2MP SECONDARY_EXPLICIT_ROUTE Object (SERO) is defined as
identical to the ERO. The class of the P2MP SERO is the same as the identical to the ERO. The class of the P2MP SERO is the same as the
skipping to change at page 45, line 8 skipping to change at page 47, line 15
The Error Value "P2MP Re-Merge Parameter Mismatch" is described in The Error Value "P2MP Re-Merge Parameter Mismatch" is described in
section 18. IANA is requested to assign value 26 to this Error Value. section 18. IANA is requested to assign value 26 to this Error Value.
The Error Value "ERO Resulted in Remerge" is described in section 18. The Error Value "ERO Resulted in Remerge" is described in section 18.
IANA is requested to assign value 27 to this Error Value. IANA is requested to assign value 27 to this Error Value.
20.4. LSP Attributes Flags 20.4. LSP Attributes Flags
IANA has been asked to manage the space of flags in the Attibutes IANA has been asked to manage the space of flags in the Attibutes
Flags TLV carried in the LSP_REQUIRED_ATTRIBUTES Object [LSP-ATTR]. Flags TLV carried in the LSP_REQUIRED_ATTRIBUTES Object [RFC4420].
This document defines a new flag as follows: This document defines a new flag as follows:
Suggested Bit Number: 3 Suggested Bit Number: 3
Meaning: LSP Integrity Required Meaning: LSP Integrity Required
Used in Attributes Flags on Path: Yes Used in Attributes Flags on Path: Yes
Used in Attributes Flags on Resv: No Used in Attributes Flags on Resv: No
Used in Attributes Flags on RRO: No Used in Attributes Flags on RRO: No
Referenced Section of this Doc: 10 Referenced Section of this Doc: 5.2.4
21. Security Considerations 21. Security Considerations
This document does not introduce any new security issues. The In principle this document does not introduce any new security issues
security issues identified in [RFC3209] and [RFC3473] are still above those identified in [RFC3209], [RFC3473] and [RFC4206].
relevant. [RFC2205] specifies the message integrity mechanisms for hop-by-hop
RSVP signaling. These mechanisms apply to the hop-by-hop P2MP RSVP-
TE signaling in this document. Further [RFC3473] and [RFC4206]
specify the security mechanisms for non hop-by-hop RSVP-TE signaling.
These mechanisms apply to the non hop-by-hop P2MP RSVP-TE signaling
specified in this document, particularly in sections 16 and 17.
An administration may wish to limit the domain over which P2MP TE
tunnels can be established. This can be accomplished by setting
filters on various ports to deny action on a RSVP path message with a
SESSION object of type P2MP_LSP_IPv4 or P2MP_LSP_IPv6.
The ingress LSR of a P2MP TE LSP, determines the leaves of the P2MP
TE LSP based on the application of the P2MP TE LSP. The specification
of how such applications will use a P2MP TE LSP is outside the scope
of this document. However these applications SHOULD provide
mechanisms to ensure that unauthorized leaves are not added to the
P2MP TE LSP.
22. Acknowledgements 22. Acknowledgements
This document is the product of many people. The contributors are This document is the product of many people. The contributors are
listed in Section 27.2. listed in Section 27.2.
Thanks to Yakov Rekhter, Der-Hwa Gan, Arthi Ayyanger and Nischal Thanks to Yakov Rekhter, Der-Hwa Gan, Arthi Ayyanger and Nischal
Sheth for their suggestions and comments. Thanks also to Dino Sheth for their suggestions and comments. Thanks also to Dino
Farninacci for his comments. Farninacci and Benjamin Niven for their comments.
23. Appendix
23.1. Example
Following is one example of setting up a P2MP LSP using the
procedures described in this document.
Source 1 (S1)
|
PE1
| |
|L5 |
P3 |
| |
L3 |L1 |L2
R2----PE3--P1 P2---PE2--Receiver 1 (R1)
| L4
PE5----PE4----R3
|
|
R4
Figure 2.
The mechanism is explained using Figure 2. PE1 is the ingress-LSR.
PE2, PE3 and PE4 are Egress-LSRs.
a) PE1 learns that PE2, PE3 and PE4 are interested in joining a P2MP
tree with a P2MP ID of P2MP ID1. We assume that PE1 learns of the
egress-LSRs at different points.
b) PE1 computes the P2P path to reach PE2.
c) PE1 establishes the S2L sub-LSP to PE2 along <PE1, P2, PE2>
d) PE1 computes the P2P path to reach PE3 when it discovers PE3. This
path is computed to share the same links where possible with the sub-
LSP to PE2 as they belong to the same P2MP session.
e) PE1 establishes the S2L sub-LSP to PE3 along <PE1, P3, P1, PE3>
f) PE1 computes the P2P path to reach PE4 when it discovers PE4. This
path is computed to share the same links where possible with the sub-
LSPs to PE2 and PE3 as they belong to the same P2MP session.
g) PE1 signals the Path message for PE4 sub-LSP along <PE1, P3, P1,
PE4>
e) P1 receives a Resv message from PE4 with label L4. It had
previously received a Resv message from PE3 with label L3. It had
allocated a label L1 for the sub-LSP to PE3. It uses the same label
and sends the Resv messages to P3. Note that it may send only one
Resv message with multiple flow descriptors in the flow descriptor
list. If this is the case and FF style is used, the FF flow
descriptor will contain the S2L sub-LSP descriptor list with two
entries: one for PE4 and the other for PE3. For SE style, the SE
filter spec will contain this S2L sub-LSP descriptor list. P1 also
creates a label mapping of (L1 -> {L3, L4}). P3 uses the existing
label L5 and sends the Resv message to PE1, with label L5. It reuses
the label mapping of {L5 -> L1}.
24. References 23. References
24.1. Normative References 23.1. Normative References
[RFC4206] K. Kompella, Y. Rekhter, "LSP Hierarchy with Generalized [RFC4206] K. Kompella, Y. Rekhter, "LSP Hierarchy with Generalized
MPLS TE" [RFC4206] MPLS TE" [RFC4206]
[LSP-ATTR] A. Farrel, et. al. , "Encoding of [RFC4420] A. Farrel, et. al. , "Encoding of
Attributes for Multiprotocol Label Switching (MPLS) Attributes for Multiprotocol Label Switching (MPLS)
Label Switched Path (LSP) Establishment Using RSVP-TE", Label Switched Path (LSP) Establishment Using RSVP-TE",
draft-ietf-mpls-rsvpte-attributes-05.txt, March 2004, RFC 4420, February 2006.
work in progress.
[RFC3209] D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, [RFC3209] D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan,
G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels",
RFC3209, December 2001, work in progress. RFC3209, December 2001, work in progress.
[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, work in Requirement Levels", BCP 14, RFC 2119, March 1997, work in
progress. progress.
[RFC2205] Braden, R., Zhang, L., Berson, S., Herzog, S. and [RFC2205] Braden, R., Zhang, L., Berson, S., Herzog, S. and
skipping to change at page 47, line 39 skipping to change at page 48, line 47
September 1997, work in progress. September 1997, work in progress.
[RFC3471] Lou Berger, et al., "Generalized MPLS - Signaling [RFC3471] Lou Berger, et al., "Generalized MPLS - Signaling
Functional Description", RFC 3471, January 2003, work in Functional Description", RFC 3471, January 2003, work in
progress. progress.
[RFC3473] L. Berger et.al., "Generalized MPLS Signaling - RSVP-TE [RFC3473] L. Berger et.al., "Generalized MPLS Signaling - RSVP-TE
Extensions", RFC 3473, January 2003, work in progress. Extensions", RFC 3473, January 2003, work in progress.
[RFC2961] L. Berger, D. Gan, G. Swallow, P. Pan, F. Tommasi, [RFC2961] L. Berger, D. Gan, G. Swallow, P. Pan, F. Tommasi,
S. Molendini, "RSVP Refresh Overhead Reduction Extensions" S. Molendini, "RSVP Refresh Overhead Reduction
, RFC 2961, April 2001, work in progress. Extensons", RFC 2961, April 2001, work in progress.
[RFC3031] Rosen, E., Viswanathan, A. and R. Callon, "Multiprotocol [RFC3031] Rosen, E., Viswanathan, A. and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031, January 2001, Label Switching Architecture", RFC 3031, January 2001,
work in progress. work in progress.
[RFC4090] P. Pan, G. Swallow, A. Atlas (Editors), "Fast Reroute [RFC4090] P. Pan, G. Swallow, A. Atlas (Editors), "Fast Reroute
Extensions to RSVP-TE for LSP Tunnels", work in progress. Extensions to RSVP-TE for LSP Tunnels", work in progress.
[RFC3477] K. Kompella, Y. Rekther, "Signalling Unnumbered Links in [RFC3477] K. Kompella, Y. Rekther, "Signalling Unnumbered Links in
Resource ReSerVation Protocol - Traffic Engineering Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", work in progress. (RSVP-TE)", work in progress.
[RFC4461] S. Yasukawa, Editor "Signaling Requirements for [RFC4461] S. Yasukawa, Editor "Signaling Requirements for
Point-to-Multipoint Traffic Engineered MPLS LSPs", RFC4461. Point-to-Multipoint Traffic Engineered MPLS LSPs", RFC4461.
[RECOVERY] "GMPLS Based Segment Recovery", [RECOVERY] "GMPLS Based Segment Recovery",
draft-ietf-ccamp-gmpls-segment-recovery-02.txt draft-ietf-ccamp-gmpls-segment-recovery-02.txt
24.2. Informative References 23.2. Informative References
[BFD] D. Katz, D. Ward, "Bidirectional Forwarding Detection", [BFD] D. Katz, D. Ward, "Bidirectional Forwarding Detection",
draft-ietf-bfd-02.txt, work in progress. draft-ietf-bfd-base-05.txt, work in progress.
[BFD-MPLS] R. Aggarwal, K. Kompella, T. Nadeau, G. Swallow, "BFD for [BFD-MPLS] R. Aggarwal, K. Kompella, T. Nadeau, G. Swallow, "BFD for
MPLS LSPs", draft-ietf-bfd-mpls-01.txt, work in progress. MPLS LSPs", draft-ietf-bfd-mpls-02.txt, work in progress.
[IPR-1] Bradner, S., "IETF Rights in Contributions", BCP 78,
RFC 3667, February 2004, work in progress.
[IPR-2] Bradner, S., Ed., "Intellectual Property Rights in IETF
Technology", BCP 79, RFC 3668, February 2004, work in
progress.
[INT-REG] A. Farrel, J.P. Vasseur, and A. Ayyangar, "A Framework for
Inter-Domain MPLS Traffic Engineering",
draft-ietf-ccamp-inter-domain-framework-04.txt, work in
progress.
[RFC2209] R. Braden, L. Zhang, "Resource Reservation Protocol (RSVP)
Version 1 Message Processing Rules", RFC 2209, work in
progress.
[LSP-STITCH] A. Ayyanger, J.P. Vasseur, "Label Switched Path [LSP-STITCH] A. Ayyanger, J.P. Vasseur, "Label Switched Path
Stitching with Generalized MPLS Traffic Engineering", Stitching with Generalized MPLS Traffic Engineering",
work in progress work in progress
[TE-NODE-CAP] JP Vasseur, JL Le Roux, et al. "Routing extensions for [TE-NODE-CAP] JP Vasseur, JL Le Roux, et al. "Routing extensions for
discovery of Traffic Engineering Node Capabilities", discovery of Traffic Engineering Node Capabilities",
draft-vasseur-ccamp-te-node-cap-00.txt, February 2005, draft-ietf-ccamp-te-node-cap-01.txt, June 2006,
work in progress work in progress
[RFC4003] L. Berger, "GMPLS Signaling Procedure for Egress [RFC4003] L. Berger, "GMPLS Signaling Procedure for Egress
Control", February, 2005. Control", February, 2005.
24. Appendix
24.1. Example
Following is one example of setting up a P2MP LSP using the
procedures described in this document.
Source 1 (S1)
|
PE1
| |
|L5 |
P3 |
| |
L3 |L1 |L2
R2----PE3--P1 P2---PE2--Receiver 1 (R1)
| L4
PE5----PE4----R3
|
|
R4
Figure 2.
The mechanism is explained using Figure 2. PE1 is the ingress-LSR.
PE2, PE3 and PE4 are Egress-LSRs.
a) PE1 learns that PE2, PE3 and PE4 are interested in joining a P2MP
tree with a P2MP ID of P2MP ID1. We assume that PE1 learns of the
egress-LSRs at different points in time.
b) PE1 computes the P2P path to reach PE2.
c) PE1 establishes the S2L sub-LSP to PE2 along <PE1, P2, PE2>
d) PE1 computes the P2P path to reach PE3 when it discovers PE3. This
path is computed to share the same links where possible with the sub-
LSP to PE2 as they belong to the same P2MP session.
e) PE1 establishes the S2L sub-LSP to PE3 along <PE1, P3, P1, PE3>
f) PE1 computes the P2P path to reach PE4 when it discovers PE4. This
path is computed to share the same links where possible with the sub-
LSPs to PE2 and PE3 as they belong to the same P2MP session.
g) PE1 signals the Path message for PE4 sub-LSP along <PE1, P3, P1,
PE4>
e) P1 receives a Resv message from PE4 with label L4. It had
previously received a Resv message from PE3 with label L3. It had
allocated a label L1 for the sub-LSP to PE3. It uses the same label
and sends the Resv messages to P3. Note that it may send only one
Resv message with multiple flow descriptors in the flow descriptor
list. If this is the case and FF style is used, the FF flow
descriptor will contain the S2L sub-LSP descriptor list with two
entries: one for PE4 and the other for PE3. For SE style, the SE
filter spec will contain this S2L sub-LSP descriptor list. P1 also
creates a label mapping of (L1 -> {L3, L4}). P3 uses the existing
label L5 and sends the Resv message to PE1, with label L5. It reuses
the label mapping of {L5 -> L1}.
25. Author Information 25. Author Information
25.1. Editor Information 25.1. Editor Information
Rahul Aggarwal Rahul Aggarwal
Juniper Networks Juniper Networks
1194 North Mathilda Ave. 1194 North Mathilda Ave.
Sunnyvale, CA 94089 Sunnyvale, CA 94089
Email: rahul@juniper.net Email: rahul@juniper.net
skipping to change at page 49, line 42 skipping to change at page 52, line 18
Boeing Boeing
Email: john.E.Drake2@boeing.com Email: john.E.Drake2@boeing.com
Alan Kullberg Alan Kullberg
Motorola Computer Group Motorola Computer Group
120 Turnpike Road 1st Floor 120 Turnpike Road 1st Floor
Southborough, MA 01772 Southborough, MA 01772
EMail: alan.kullberg@motorola.com EMail: alan.kullberg@motorola.com
Lou Berger Lou Berger
Movaz Networks, Inc. LabN Consulting, L.L.C.
7926 Jones Branch Drive EMail: lberger@labn.net
Suite 615
McLean VA, 22102
Phone: +1 703 847-1801
EMail: lberger@movaz.com
Liming Wei Liming Wei
Redback Networks Redback Networks
350 Holger Way 350 Holger Way
San Jose, CA 95134 San Jose, CA 95134
Email: lwei@redback.com Email: lwei@redback.com
George Apostolopoulos George Apostolopoulos
Redback Networks Redback Networks
350 Holger Way 350 Holger Way
skipping to change at page 51, line 33 skipping to change at page 53, line 51
9-11, Midori-Cho 3-Chome 9-11, Midori-Cho 3-Chome
Musashino-Shi, Tokyo 180-8585 Japan Musashino-Shi, Tokyo 180-8585 Japan
Phone: +81 422 59 4804 Phone: +81 422 59 4804
EMail: uga.masanori@lab.ntt.co.jp EMail: uga.masanori@lab.ntt.co.jp
Igor Bryskin Igor Bryskin
Movaz Networks, Inc. Movaz Networks, Inc.
7926 Jones Branch Drive 7926 Jones Branch Drive
Suite 615 Suite 615
McLean VA, 22102 McLean VA, 22102
ibryskin@movaz.com
Adrian Farrel Adrian Farrel
Old Dog Consulting Old Dog Consulting
Phone: +44 0 1978 860944 Phone: +44 0 1978 860944
EMail: adrian@olddog.co.uk EMail: adrian@olddog.co.uk
Jean-Louis Le Roux Jean-Louis Le Roux
France Telecom France Telecom
2, avenue Pierre-Marzin 2, avenue Pierre-Marzin
22307 Lannion Cedex 22307 Lannion Cedex
France France
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