draft-ietf-mpls-mp-ldp-reqs-07.txt | draft-ietf-mpls-mp-ldp-reqs-08.txt | |||
---|---|---|---|---|
MPLS J. Le Roux, Ed. | MPLS J. Le Roux, Ed. | |||
Internet-Draft T. Morin, Ed. | Internet-Draft T. Morin, Ed. | |||
Intended status: Historic France Telecom - Orange | Intended status: Historic France Telecom - Orange | |||
Expires: November 13, 2011 May 12, 2011 | Expires: November 27, 2011 May 26, 2011 | |||
Requirements for Point-To-Multipoint Extensions to the Label | Requirements for Point-To-Multipoint Extensions to the Label | |||
Distribution Protocol | Distribution Protocol | |||
draft-ietf-mpls-mp-ldp-reqs-07 | draft-ietf-mpls-mp-ldp-reqs-08 | |||
Abstract | Abstract | |||
This document lists a set of functional requirements that served as | This document lists a set of functional requirements that served as | |||
input to the design of Label Distribution Protocol (LDP) extensions | input to the design of Label Distribution Protocol (LDP) extensions | |||
for setting up point-to-multipoint (P2MP) Label Switched Paths (LSP), | for setting up point-to-multipoint (P2MP) Label Switched Paths (LSP), | |||
in order to deliver point-to-multipoint applications over a Multi | in order to deliver point-to-multipoint applications over a Multi | |||
Protocol Label Switching (MPLS) infrastructure. | Protocol Label Switching (MPLS) infrastructure. | |||
Requirements Language | ||||
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | ||||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | ||||
document are to be interpreted as described in [RFC2119]. | ||||
Status of this Memo | Status of this Memo | |||
This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
This Internet-Draft will expire on November 13, 2011. | This Internet-Draft will expire on November 27, 2011. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2011 IETF Trust and the persons identified as the | Copyright (c) 2011 IETF Trust and the persons identified as the | |||
document authors. All rights reserved. | document authors. All rights reserved. | |||
This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
(http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
publication of this document. Please review these documents | publication of this document. Please review these documents | |||
skipping to change at page 3, line 7 | skipping to change at page 3, line 7 | |||
modifications of such material outside the IETF Standards Process. | modifications of such material outside the IETF Standards Process. | |||
Without obtaining an adequate license from the person(s) controlling | Without obtaining an adequate license from the person(s) controlling | |||
the copyright in such materials, this document may not be modified | the copyright in such materials, this document may not be modified | |||
outside the IETF Standards Process, and derivative works of it may | outside the IETF Standards Process, and derivative works of it may | |||
not be created outside the IETF Standards Process, except to format | not be created outside the IETF Standards Process, except to format | |||
it for publication as an RFC or to translate it into languages other | it for publication as an RFC or to translate it into languages other | |||
than English. | than English. | |||
Table of Contents | Table of Contents | |||
1. Contributing Authors . . . . . . . . . . . . . . . . . . . . . 4 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 | |||
2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 1.1. Contributing Authors . . . . . . . . . . . . . . . . . . . 4 | |||
2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4 | |||
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 | 1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 | 1.4. Context and Motivations . . . . . . . . . . . . . . . . . 6 | |||
4. Requirements overview . . . . . . . . . . . . . . . . . . . . 7 | 1.5. Document Scope . . . . . . . . . . . . . . . . . . . . . . 7 | |||
5. Application scenario . . . . . . . . . . . . . . . . . . . . . 7 | 2. Requirements Overview . . . . . . . . . . . . . . . . . . . . 7 | |||
6. Detailed Requirements . . . . . . . . . . . . . . . . . . . . 9 | 3. Application Scenario . . . . . . . . . . . . . . . . . . . . . 8 | |||
6.1. P2MP LSPs . . . . . . . . . . . . . . . . . . . . . . . . 9 | 4. Detailed Requirements . . . . . . . . . . . . . . . . . . . . 9 | |||
6.2. P2MP LSP FEC . . . . . . . . . . . . . . . . . . . . . . . 9 | 4.1. P2MP LSPs . . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
6.3. P2MP LDP routing . . . . . . . . . . . . . . . . . . . . . 9 | 4.2. P2MP LSP FEC . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
6.4. Setting up, tearing down and modifying P2MP LSPs . . . . . 10 | 4.3. P2MP LDP Routing . . . . . . . . . . . . . . . . . . . . . 10 | |||
6.5. Label Advertisement . . . . . . . . . . . . . . . . . . . 10 | 4.4. Setting Up, Tearing Down and Modifying P2MP LSPs . . . . . 10 | |||
6.6. Data Duplication . . . . . . . . . . . . . . . . . . . . . 10 | 4.5. Label Advertisement . . . . . . . . . . . . . . . . . . . 10 | |||
6.7. Detecting and Avoiding Loops . . . . . . . . . . . . . . . 10 | 4.6. Data Duplication . . . . . . . . . . . . . . . . . . . . . 10 | |||
6.8. P2MP LSP Re-routing . . . . . . . . . . . . . . . . . . . 11 | 4.7. Detecting and Avoiding Loops . . . . . . . . . . . . . . . 11 | |||
6.9. Support for multi-access networks . . . . . . . . . . . . 12 | 4.8. P2MP LSP Re-routing . . . . . . . . . . . . . . . . . . . 11 | |||
6.10. Support for encapsulation in P2P and P2MP TE tunnels . . . 12 | 4.9. Support for Multi-Access Networks . . . . . . . . . . . . 12 | |||
6.11. Label spaces . . . . . . . . . . . . . . . . . . . . . . . 12 | 4.10. Support for Encapsulation in P2P and P2MP TE Tunnels . . . 12 | |||
6.12. IPv4/IPv6 support . . . . . . . . . . . . . . . . . . . . 12 | 4.11. Label Spaces . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
6.13. Multi-Area/AS LSPs . . . . . . . . . . . . . . . . . . . . 13 | 4.12. IPv4/IPv6 Support . . . . . . . . . . . . . . . . . . . . 13 | |||
6.14. OAM . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 | 4.13. Multi-Area/AS LSPs . . . . . . . . . . . . . . . . . . . . 13 | |||
6.15. Graceful Restart and Fault Recovery . . . . . . . . . . . 13 | 4.14. OAM . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
6.16. Robustness . . . . . . . . . . . . . . . . . . . . . . . . 13 | 4.15. Graceful Restart and Fault Recovery . . . . . . . . . . . 13 | |||
6.17. Scalability . . . . . . . . . . . . . . . . . . . . . . . 13 | 4.16. Robustness . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
6.18. Backward Compatibility . . . . . . . . . . . . . . . . . . 14 | 4.17. Scalability . . . . . . . . . . . . . . . . . . . . . . . 14 | |||
7. Shared Trees . . . . . . . . . . . . . . . . . . . . . . . . . 14 | 4.18. Backward Compatibility . . . . . . . . . . . . . . . . . . 14 | |||
7.1. Requirements for MP2MP LSPs . . . . . . . . . . . . . . . 15 | 5. Shared Trees . . . . . . . . . . . . . . . . . . . . . . . . . 14 | |||
8. Evaluation criteria . . . . . . . . . . . . . . . . . . . . . 16 | 5.1. Requirements for MP2MP LSPs . . . . . . . . . . . . . . . 15 | |||
8.1. Performance . . . . . . . . . . . . . . . . . . . . . . . 16 | 6. Evaluation Criteria . . . . . . . . . . . . . . . . . . . . . 16 | |||
8.2. Complexity and Risks . . . . . . . . . . . . . . . . . . . 16 | 6.1. Performance . . . . . . . . . . . . . . . . . . . . . . . 16 | |||
9. Security Considerations . . . . . . . . . . . . . . . . . . . 16 | 6.2. Complexity and Risks . . . . . . . . . . . . . . . . . . . 17 | |||
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17 | 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 | |||
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 | 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17 | |||
12.1. Normative References . . . . . . . . . . . . . . . . . . . 17 | 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 | |||
12.2. Informative References . . . . . . . . . . . . . . . . . . 18 | 10.1. Normative References . . . . . . . . . . . . . . . . . . . 17 | |||
10.2. Informative References . . . . . . . . . . . . . . . . . . 18 | ||||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 | |||
1. Contributing Authors | 1. Introduction | |||
This document lists a set of functional requirements that served as | ||||
input to the design of Label Distribution Protocol (LDP) extensions | ||||
for setting up point-to-multipoint (P2MP) Label Switched Paths | ||||
(LSP)[I-D.ietf-mpls-ldp-p2mp], in order to deliver point-to- | ||||
multipoint applications over a Multi-Protocol Label Switching (MPLS) | ||||
infrastructure. It is published with Historic status with the | ||||
perspective of documenting the work done. | ||||
The document is structured as follows: | ||||
o Section 2 is an overview of the requirements; | ||||
o Section 3 illustrates an application scenario; | ||||
o Section 4 addresses detailed requirements for P2MP LSPs; | ||||
o Section 5 finally discusses requirements for shared trees and | ||||
MultiPoint-to-MultiPoint (MP2MP) LSPs. | ||||
1.1. Contributing Authors | ||||
The following people contributed to the text and content of this | The following people contributed to the text and content of this | |||
document: | document: | |||
o Shane Amante, Level 3 Communications, LLC | o Shane Amante, Level 3 Communications, LLC | |||
o Luyuan Fang, Cisco Systems | o Luyuan Fang, Cisco Systems | |||
o Yuji Kamite, NTT Communications Corporation | o Yuji Kamite, NTT Communications Corporation | |||
o Jean-Louis Le Roux, France Telecom - Orange | o Jean-Louis Le Roux, France Telecom - Orange | |||
o Thomas Morin, France Telecom - Orange | o Thomas Morin, France Telecom - Orange | |||
o Vincent Parfait, France Telecom - Orange, Orange Business Services | o Vincent Parfait, France Telecom - Orange, Orange Business Services | |||
o Lei Wang, Telenor | o Lei Wang, Telenor | |||
2. Definitions | 1.2. Requirements Language | |||
2.1. Acronyms | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | ||||
document are to be interpreted as described in [RFC2119]. | ||||
1.3. Definitions | ||||
1.3.1. Acronyms | ||||
P2P: Point-To-Point | P2P: Point-To-Point | |||
MP2P: Multipoint-to-Point | MP2P: Multipoint-to-Point | |||
P2MP: Point-To-MultiPoint | P2MP: Point-To-MultiPoint | |||
MP2MP: MultiPoint-To-Multipoint | MP2MP: MultiPoint-To-Multipoint | |||
LSP: Label Switched Path | LSP: Label Switched Path | |||
skipping to change at page 5, line 5 | skipping to change at page 5, line 29 | |||
LSR: Label Switching Router | LSR: Label Switching Router | |||
PE: Provider Edge router | PE: Provider Edge router | |||
P: Provider router | P: Provider router | |||
IGP: Interior Gateway Protocol | IGP: Interior Gateway Protocol | |||
AS: Autonomous System | AS: Autonomous System | |||
2.2. Terminology | 1.3.2. Terminology | |||
The reader is assumed to be familiar with the terminology in | The reader is assumed to be familiar with the terminology in | |||
[RFC3031], [RFC5036], and [RFC4026]. | [RFC3031], [RFC5036], and [RFC4026]. | |||
Ingress LSR: | Ingress LSR: | |||
Router acting as a sender of an LSP | Router acting as a sender of an LSP | |||
Egress LSR: | Egress LSR: | |||
Router acting as a receiver of an LSP | Router acting as a receiver of an LSP | |||
P2P LSP: | P2P LSP: | |||
A LSP that has one unique Ingress LSR and one unique Egress LSR | An LSP that has one unique Ingress LSR and one unique Egress LSR | |||
MP2P LSP: | MP2P LSP: | |||
A LSP that has one or more Ingress LSRs and one unique Egress LSR | An LSP that has one or more Ingress LSRs and one unique Egress LSR | |||
P2MP LSP: | P2MP LSP: | |||
A LSP that has one unique Ingress LSR and one or more Egress LSRs | An LSP that has one unique Ingress LSR and one or more Egress LSRs | |||
MP2MP LSP: | MP2MP LSP: | |||
A LSP that as one or more Leaf LSRs acting indifferently as | An LSP that as one or more Leaf LSRs acting indifferently as | |||
Ingress or Egress LSR | Ingress or Egress LSR | |||
Leaf LSR: | Leaf LSR: | |||
Egress LSR of a P2MP LSP or Ingress/Egress LSR of a MP2MP LSP | An Egress LSR of a P2MP LSP or an Ingress/Egress LSR of a MP2MP | |||
LSP | ||||
Transit LSR: | Transit LSR: | |||
A LSR of a P2MP or MP2MP LSP that has one or more Downstream LSRs | An LSR of a P2MP or MP2MP LSP that has one or more Downstream LSRs | |||
Branch LSR: | Branch LSR: | |||
A LSR of a P2MP or MP2MP LSP that has more than one downstream LSR | An LSR of a P2MP or MP2MP LSP that has more than one downstream | |||
LSR | ||||
Bud LSR: | Bud LSR: | |||
A LSR of a P2MP or MP2MP LSP that is an egress but also has one or | An LSR of a P2MP or MP2MP LSP that is an egress but also has one | |||
more directly connected downstream LSR(s) | or more directly connected downstream LSR(s) | |||
P2MP tree: | P2MP tree: | |||
The ordered set of LSRs and links that comprise the path of a P2MP | The ordered set of LSRs and links that comprise the path of a P2MP | |||
LSP from its ingress LSR to all of its egress LSRs. | LSP from its ingress LSR to all of its egress LSRs. | |||
3. Introduction | 1.4. Context and Motivations | |||
Note that this document captures requirements that served as input to | ||||
the design of [I-D.ietf-mpls-ldp-p2mp] and is published with Historic | ||||
status with the perspective of documenting the work done. | ||||
LDP [RFC5036] has been deployed for setting up point-to-point (P2P) | LDP [RFC5036] has been deployed for setting up point-to-point (P2P) | |||
and multipoint-to-point (MP2P) LSPs, in order to offer point-to-point | and multipoint-to-point (MP2P) LSPs, in order to offer point-to-point | |||
services in MPLS backbones. | services in MPLS backbones. | |||
There are emerging requirements for supporting delivery of point-to- | There are emerging requirements for supporting delivery of point-to- | |||
multipoint applications in MPLS backbones, such as those defined in | multipoint applications in MPLS backbones, such as those defined in | |||
[RFC4834] and [RFC5501]. | [RFC4834] and [RFC5501]. | |||
For various reasons, including consistency with P2P applications, and | For various reasons, including consistency with P2P applications, and | |||
skipping to change at page 6, line 39 | skipping to change at page 7, line 11 | |||
are needed (Optimization, QoS, Fast recovery). | are needed (Optimization, QoS, Fast recovery). | |||
However for operators who want to support point-to-multipoint traffic | However for operators who want to support point-to-multipoint traffic | |||
delivery on an MPLS backbone, without Traffic Engineering needs, and | delivery on an MPLS backbone, without Traffic Engineering needs, and | |||
who have already deployed LDP for P2P traffic, an interesting and | who have already deployed LDP for P2P traffic, an interesting and | |||
useful approach would be to rely on LDP extensions in order to setup | useful approach would be to rely on LDP extensions in order to setup | |||
point-to-multipoint (P2MP) LSPs. This would bring consistency with | point-to-multipoint (P2MP) LSPs. This would bring consistency with | |||
P2P MPLS applications and would ease the delivery of point-to- | P2P MPLS applications and would ease the delivery of point-to- | |||
multipoint services in an MPLS backbone. | multipoint services in an MPLS backbone. | |||
1.5. Document Scope | ||||
This document focuses on the LDP approach for setting up P2MP LSPs. | This document focuses on the LDP approach for setting up P2MP LSPs. | |||
It lists a detailed set of requirements for P2MP extensions to LDP, | It lists a detailed set of requirements for P2MP extensions to LDP, | |||
so as to deliver P2MP traffic over a LDP-enabled MPLS infrastructure. | so as to deliver P2MP traffic over a LDP-enabled MPLS infrastructure. | |||
The original intent was that these requirements should be used as | The original intent was that these requirements should be used as | |||
guidelines when specifying LDP extensions. | guidelines when specifying LDP extensions. | |||
Note that generic requirements for P2MP extensions to MPLS are out of | Note that generic requirements for P2MP extensions to MPLS are out of | |||
the scope of this document. Rather this document describes solution | the scope of this document. Rather this document describes solution | |||
specific requirements related to LDP extensions in order to set up | specific requirements related to LDP extensions in order to set up | |||
P2MP LSPs. | P2MP LSPs. | |||
Note also that other mechanisms could be used for setting up P2MP | Note also that other mechanisms could be used for setting up P2MP | |||
LSPs, such as for instance PIM extensions, but these are out of the | LSPs, such as for instance PIM extensions, but these are out of the | |||
scope of this document. The objective is not to compare these | scope of this document. The objective is not to compare these | |||
mechanisms but rather to focus on the requirements for an LDP | mechanisms but rather to focus on the requirements for an LDP | |||
extension approach. | extension approach. | |||
The document is structured as follows: | 2. Requirements Overview | |||
o Section 4 is an overview of the requirements; | ||||
o Section 5 illustrates an application scenario; | ||||
o Section 6 addresses detailed requirements for P2MP LSPs; | ||||
o Section 7 finally discusses requirements for shared trees and | ||||
MultiPoint-to-MultiPoint (MP2MP) LSPs. | ||||
4. Requirements overview | ||||
The P2MP LDP mechanism MUST support setting up P2MP LSPs, i.e. LSPs | The P2MP LDP mechanism MUST support setting up P2MP LSPs, i.e. LSPs | |||
with one Ingress LSR and one or more Egress LSRs, with traffic | with one Ingress LSR and one or more Egress LSRs, with traffic | |||
replication at some Branch LSRs. | replication at some Branch LSRs. | |||
The P2MP LDP mechanism MUST allow the addition or removal of leaves | The P2MP LDP mechanism MUST allow the addition or removal of leaves | |||
associated with a P2MP LSP. | associated with a P2MP LSP. | |||
The P2MP LDP mechanism MUST co-exist with current LDP mechanisms and | The P2MP LDP mechanism MUST co-exist with current LDP mechanisms and | |||
inherit its capability sets from [RFC5036]. It is of paramount | inherit its capability sets from [RFC5036]. It is of paramount | |||
skipping to change at page 7, line 41 | skipping to change at page 8, line 6 | |||
exist with P2P and P2MP RSVP-TE mechanisms [RFC3209], [RFC4875]. It | exist with P2P and P2MP RSVP-TE mechanisms [RFC3209], [RFC4875]. It | |||
is of paramount importance that the P2MP LDP mechanism MUST NOT | is of paramount importance that the P2MP LDP mechanism MUST NOT | |||
impede the operation of existing P2P and P2MP RSVP-TE LSPs. | impede the operation of existing P2P and P2MP RSVP-TE LSPs. | |||
The P2MP LDP mechanism MAY also allow setting up multipoint-to- | The P2MP LDP mechanism MAY also allow setting up multipoint-to- | |||
multipoint (MP2MP) LSPs connecting a group of Leaf LSRs acting | multipoint (MP2MP) LSPs connecting a group of Leaf LSRs acting | |||
indifferently as Ingress LSR or Egress LSR. This may allow a | indifferently as Ingress LSR or Egress LSR. This may allow a | |||
reduction in the amount of LDP state that needs to be maintained by a | reduction in the amount of LDP state that needs to be maintained by a | |||
LSR. | LSR. | |||
5. Application scenario | 3. Application Scenario | |||
Figure 1 below illustrates an LDP enabled MPLS provider network, used | Figure 1 below illustrates an LDP enabled MPLS provider network, used | |||
to carry both unicast and multicast traffic of VPN customers | to carry both unicast and multicast traffic of VPN customers | |||
following for instance the architecture defined in | following for instance the architecture defined in | |||
[I-D.ietf-l3vpn-2547bis-mcast] for BGP/MPLS VPNs, or the one defined | [I-D.ietf-l3vpn-2547bis-mcast] for BGP/MPLS VPNs, or the one defined | |||
in [I-D.ietf-l2vpn-vpls-mcast]. | in [I-D.ietf-l2vpn-vpls-mcast]. | |||
In this example, a set of MP2P LDP LSPs are setup between Provider | In this example, a set of MP2P LDP LSPs are setup between Provider | |||
Edge (PE) routers to carry unicast VPN traffic within the MPLS | Edge (PE) routers to carry unicast VPN traffic within the MPLS | |||
backbone. | backbone. | |||
skipping to change at page 9, line 11 | skipping to change at page 9, line 24 | |||
*| |* | *| |* | |||
*| |* | *| |* | |||
PE5 PE6 | PE5 PE6 | |||
Figure 2: Attachment of PE5 and PE6. | Figure 2: Attachment of PE5 and PE6. | |||
The above example is provided for the sake of illustration. Note | The above example is provided for the sake of illustration. Note | |||
that P2MP LSPs ingress and egress LSRs may not necessarily be PE | that P2MP LSPs ingress and egress LSRs may not necessarily be PE | |||
routers. Also branch LSRs may not necessarily be P routers. | routers. Also branch LSRs may not necessarily be P routers. | |||
6. Detailed Requirements | 4. Detailed Requirements | |||
6.1. P2MP LSPs | 4.1. P2MP LSPs | |||
The P2MP LDP mechanism MUST support setting up P2MP LSPs. Data plane | The P2MP LDP mechanism MUST support setting up P2MP LSPs. Data plane | |||
aspects related to P2MP LSPs are those already defined in [RFC4461]. | aspects related to P2MP LSPs are those already defined in [RFC4461]. | |||
That is, a P2MP LSP has one Ingress LSR and one or more Egress LSRs. | That is, a P2MP LSP has one Ingress LSR and one or more Egress LSRs. | |||
Traffic sent by the Ingress LSR is received by all Egress LSRs. The | Traffic sent by the Ingress LSR is received by all Egress LSRs. The | |||
specific aspects related to P2MP LSPs is the action required at a | specific aspects related to P2MP LSPs is the action required at a | |||
Branch LSR, where data replication occurs. Incoming labelled data is | Branch LSR, where data replication occurs. Incoming labelled data is | |||
appropriately replicated to several outgoing interfaces which may use | appropriately replicated to several outgoing interfaces which may use | |||
different labels. | different labels. | |||
An LSR SHOULD NOT send more than one copy of a packet on any given | An LSR SHOULD NOT send more than one copy of a packet on any given | |||
link of a P2MP LSP. Exceptions to this are mentioned in Section 6.9 | link of a P2MP LSP. Exceptions to this are mentioned in Section 4.9 | |||
and Section 6.18. | and Section 4.18. | |||
A P2MP LSP MUST be identified by a constant and unique identifier | A P2MP LSP MUST be identified by a constant and unique identifier | |||
within the whole LDP domain, whatever the number of leaves, which may | within the whole LDP domain, whatever the number of leaves, which may | |||
vary dynamically. This identifier will be used so as to add/remove | vary dynamically. This identifier will be used so as to add/remove | |||
leaves to/from the P2MP tree. | leaves to/from the P2MP tree. | |||
6.2. P2MP LSP FEC | 4.2. P2MP LSP FEC | |||
As with P2P MPLS technology [RFC5036], traffic MUST be classified | As with P2P MPLS technology [RFC5036], traffic MUST be classified | |||
into a FEC in this P2MP extension. All packets which belong to a | into a FEC in this P2MP extension. All packets which belong to a | |||
particular P2MP FEC and which travel from a particular node MUST use | particular P2MP FEC and which travel from a particular node MUST use | |||
the same P2MP LSP. | the same P2MP LSP. | |||
If existing FECs cannot be used for this purpose, a new LDP FEC that | If existing FECs cannot be used for this purpose, a new LDP FEC that | |||
is suitable for P2MP forwarding MUST be specified. | is suitable for P2MP forwarding MUST be specified. | |||
6.3. P2MP LDP routing | 4.3. P2MP LDP Routing | |||
As with P2P and MP2P LDP LSPs, the P2MP LDP mechanism MUST support | As with P2P and MP2P LDP LSPs, the P2MP LDP mechanism MUST support | |||
hop-by-hop LSP routing. P2MP LDP-based routing SHOULD rely upon the | hop-by-hop LSP routing. P2MP LDP-based routing SHOULD rely upon the | |||
information maintained in LSR Routing Information Bases (RIB). | information maintained in LSR Routing Information Bases (RIB). | |||
It is RECOMMENDED that the P2MP LSP routing rely upon the unicast | It is RECOMMENDED that the P2MP LSP routing rely upon the unicast | |||
route to the Ingress LSR to build a reverse path tree. | route to the Ingress LSR to build a reverse path tree. | |||
6.4. Setting up, tearing down and modifying P2MP LSPs | 4.4. Setting Up, Tearing Down and Modifying P2MP LSPs | |||
The P2MP LDP mechanism MUST support the establishment, maintenance | The P2MP LDP mechanism MUST support the establishment, maintenance | |||
and teardown of P2MP LSPs in a scalable manner. This MUST include | and teardown of P2MP LSPs in a scalable manner. This MUST include | |||
both the existence of a large amount of P2MP LSPs within a single | both the existence of a large amount of P2MP LSPs within a single | |||
network and a large amount of leaf LSRs for a single P2MP LSP (see | network and a large amount of leaf LSRs for a single P2MP LSP (see | |||
also Section 6.17 for scalability considerations and figures). | also Section 4.17 for scalability considerations and figures). | |||
In order to scale well with a large number of leaves it is | In order to scale well with a large number of leaves it is | |||
RECOMMENDED to follow a leaf-initiated P2MP LSP setup approach. For | RECOMMENDED to follow a leaf-initiated P2MP LSP setup approach. For | |||
that purpose, leaves will have to be aware of the P2MP LSP | that purpose, leaves will have to be aware of the P2MP LSP | |||
identifier. The ways a Leaf LSR discovers P2MP LSPs identifiers rely | identifier. The ways a Leaf LSR discovers P2MP LSPs identifiers rely | |||
on the applications that will use P2MP LSPs, and are out of the scope | on the applications that will use P2MP LSPs, and are out of the scope | |||
of this document. | of this document. | |||
The P2MP LDP mechanism MUST allow the dynamic addition and removal of | The P2MP LDP mechanism MUST allow the dynamic addition and removal of | |||
leaves to and from a P2MP LSP, without any restriction (provided | leaves to and from a P2MP LSP, without any restriction (provided | |||
there is network connectivity). It is RECOMMENDED that these | there is network connectivity). It is RECOMMENDED that these | |||
operations be leaf-initiated. These operations MUST NOT impact the | operations be leaf-initiated. These operations MUST NOT impact the | |||
data transfer (packet loss, duplication, delay) towards other leaves. | data transfer (packet loss, duplication, delay) towards other leaves. | |||
It is RECOMMENDED that these operations do not cause any additional | It is RECOMMENDED that these operations do not cause any additional | |||
processing except on the path from the added/removed Leaf LSR to the | processing except on the path from the added/removed Leaf LSR to the | |||
Branch LSR. | Branch LSR. | |||
6.5. Label Advertisement | 4.5. Label Advertisement | |||
The P2MP LDP mechanism MUST support downstream unsolicited label | The P2MP LDP mechanism MUST support downstream unsolicited label | |||
advertisement mode. This is well suited to a leaf-initiated approach | advertisement mode. This is well suited to a leaf-initiated approach | |||
and is consistent with P2P/MP2P LDP operations. | and is consistent with P2P/MP2P LDP operations. | |||
Other advertisement modes MAY also be supported. | Other advertisement modes MAY also be supported. | |||
6.6. Data Duplication | 4.6. Data Duplication | |||
Data duplication refers to the receipt of multiple copies of a packet | Data duplication refers to the receipt of multiple copies of a packet | |||
by any leaf. Although this may be a marginal situation, it may also | by any leaf. Although this may be a marginal situation, it may also | |||
be detrimental for certain applications. Hence, data duplication | be detrimental for certain applications. Hence, data duplication | |||
SHOULD as much as possible be avoided, and limited to (hopefully | SHOULD as much as possible be avoided, and limited to (hopefully | |||
rare) transitory conditions. | rare) transitory conditions. | |||
Note, in particular, that data duplication might occur if P2MP LSP | Note, in particular, that data duplication might occur if P2MP LSP | |||
rerouting is being performed (See also Section 6.8). | rerouting is being performed (See also Section 4.8). | |||
6.7. Detecting and Avoiding Loops | 4.7. Detecting and Avoiding Loops | |||
The P2MP LDP extension MUST have a mechanism to detect routing loops. | The P2MP LDP extension MUST have a mechanism to detect routing loops. | |||
This MAY rely on extensions to the LDP Loop detection mechanism | This MAY rely on extensions to the LDP Loop detection mechanism | |||
defined in [RFC5036]. A loop detection mechanism MAY require | defined in [RFC5036]. A loop detection mechanism MAY require | |||
recording the set of LSRs traversed on the P2MP Tree. The P2MP loop | recording the set of LSRs traversed on the P2MP Tree. The P2MP loop | |||
avoidance mechanism MUST NOT impact the scalability of the P2MP LDP | avoidance mechanism MUST NOT impact the scalability of the P2MP LDP | |||
solution. | solution. | |||
The P2MP LDP mechanism SHOULD have a mechanism to avoid routing loops | The P2MP LDP mechanism SHOULD have a mechanism to avoid routing loops | |||
in the data plane even during transient events. | in the data plane even during transient events. | |||
Furthermore, the P2MP LDP mechanism MUST avoid routing loops in the | Furthermore, the P2MP LDP mechanism MUST avoid routing loops in the | |||
data plane, that may trigger unexpected non-localized exponential | data plane, that may trigger unexpected non-localized exponential | |||
growth of traffic. | growth of traffic. | |||
6.8. P2MP LSP Re-routing | 4.8. P2MP LSP Re-routing | |||
The P2MP LDP mechanism MUST support the rerouting of a P2MP LSP in | The P2MP LDP mechanism MUST support the rerouting of a P2MP LSP in | |||
the following cases: | the following cases: | |||
o Network failure (link or node); | o Network failure (link or node); | |||
o A better path exists (e.g. new link, metric change); | o A better path exists (e.g. new link, metric change); | |||
o Planned maintenance. | o Planned maintenance. | |||
Given that P2MP LDP routing should rely on the RIB, the achievement | Given that P2MP LDP routing should rely on the RIB, the achievement | |||
of the following requirements relies on the underlying routing | of the following requirements relies on the underlying routing | |||
protocols (IGP, etc.). | protocols (IGP, etc.). | |||
6.8.1. Rerouting upon Network Failure | 4.8.1. Rerouting upon Network Failure | |||
The P2MP LDP mechanism MUST allow for rerouting of a P2MP LSP in case | The P2MP LDP mechanism MUST allow for rerouting of a P2MP LSP in case | |||
of link or node failure(s), by relying upon update of the routes in | of link or node failure(s), by relying upon update of the routes in | |||
the RIB. The rerouting time SHOULD be minimized as much as possible | the RIB. The rerouting time SHOULD be minimized as much as possible | |||
so as to reduce traffic disruption. | so as to reduce traffic disruption. | |||
A mechanism MUST be defined to prevent constant P2MP LSP teardown and | A mechanism MUST be defined to prevent constant P2MP LSP teardown and | |||
rebuild which may be caused by the instability of a specific link/ | rebuild which may be caused by the instability of a specific link/ | |||
node in the network. This can rely on IGP dampening but may be | node in the network. This can rely on IGP dampening but may be | |||
completed by specific dampening at the LDP level. | completed by specific dampening at the LDP level. | |||
6.8.2. Rerouting on a Better Path | 4.8.2. Rerouting on a Better Path | |||
The P2MP LDP mechanism MUST allow for rerouting of a P2MP LSP in case | The P2MP LDP mechanism MUST allow for rerouting of a P2MP LSP in case | |||
a better path is created in the network, for instance as a result of | a better path is created in the network, for instance as a result of | |||
a metric change, a link repair, or the addition of links or nodes. | a metric change, a link repair, or the addition of links or nodes. | |||
This will rely on update of the routes in the RIB. | This will rely on update of the routes in the RIB. | |||
6.8.3. Rerouting upon Planned Maintenance | 4.8.3. Rerouting upon Planned Maintenance | |||
The P2MP LDP mechanism MUST support planned maintenance operations. | The P2MP LDP mechanism MUST support planned maintenance operations. | |||
It MUST be possible to reroute a P2MP LSP before a link/node is | It MUST be possible to reroute a P2MP LSP before a link/node is | |||
deactivated for maintenance purposes. Traffic disruption and data | deactivated for maintenance purposes. Traffic disruption and data | |||
duplication SHOULD be minimized as much as possible during such | duplication SHOULD be minimized as much as possible during such | |||
planned maintenance. P2MP LSP rerouting upon planned maintenance MAY | planned maintenance. P2MP LSP rerouting upon planned maintenance MAY | |||
rely on a make before break procedure. | rely on a make before break procedure. | |||
6.9. Support for multi-access networks | 4.9. Support for Multi-Access Networks | |||
The P2MP LDP mechanism SHOULD provide a way for a Branch LSR to send | The P2MP LDP mechanism SHOULD provide a way for a Branch LSR to send | |||
a single copy of the data onto an interface to a multi-access network | a single copy of the data onto an interface to a multi-access network | |||
(e.g. an Ethernet LAN) and reach multiple adjacent downstream nodes. | (e.g. an Ethernet LAN) and reach multiple adjacent downstream nodes. | |||
This requires that the same label be negotiated with all downstream | This requires that the same label be negotiated with all downstream | |||
LSRs for the LSP. | LSRs for the LSP. | |||
When there are several candidate upstream LSRs on an interface to a | When there are several candidate upstream LSRs on an interface to a | |||
multi-access LAN, the P2MP LDP mechanism SHOULD provide a way for all | multi-access LAN, the P2MP LDP mechanism SHOULD provide a way for all | |||
downstream LSRs of a given P2MP LSP to select the same upstream LSR, | downstream LSRs of a given P2MP LSP to select the same upstream LSR, | |||
so as to avoid traffic replication. In addition, the P2MP LDP | so as to avoid traffic replication. In addition, the P2MP LDP | |||
mechanism SHOULD allow for an efficient balancing of a set of P2MP | mechanism SHOULD allow for an efficient balancing of a set of P2MP | |||
LSPs among a set of candidate upstream LSRs on a LAN interface. | LSPs among a set of candidate upstream LSRs on a LAN interface. | |||
6.10. Support for encapsulation in P2P and P2MP TE tunnels | 4.10. Support for Encapsulation in P2P and P2MP TE Tunnels | |||
The P2MP LDP mechanism MUST support nesting P2MP LSPs into P2P and | The P2MP LDP mechanism MUST support nesting P2MP LSPs into P2P and | |||
P2MP TE tunnels. | P2MP TE tunnels. | |||
The P2MP LDP mechanism MUST provide a way for a Branch LSR of a P2MP | The P2MP LDP mechanism MUST provide a way for a Branch LSR of a P2MP | |||
LSP, which is also a Head End LSR of a P2MP TE tunnel, to send a | LSP, which is also a Head End LSR of a P2MP TE tunnel, to send a | |||
single copy of the data onto the tunnel and reach all downstream LSRs | single copy of the data onto the tunnel and reach all downstream LSRs | |||
on the P2MP LSP, which are also Egress LSRs of the tunnel. As with | on the P2MP LSP, which are also Egress LSRs of the tunnel. As with | |||
LAN interfaces, this requires that the same label be negotiated with | LAN interfaces, this requires that the same label be negotiated with | |||
all downstream LSRs of the P2MP LDP LSP. | all downstream LSRs of the P2MP LDP LSP. | |||
6.11. Label spaces | 4.11. Label Spaces | |||
Labels for P2MP LSPs and P2P/MP2P LSPs MAY be assigned from shared or | Labels for P2MP LSPs and P2P/MP2P LSPs MAY be assigned from shared or | |||
dedicated label spaces. | dedicated label spaces. | |||
Note that dedicated label spaces will require the establishment of | Note that dedicated label spaces will require the establishment of | |||
separate P2P and P2MP LDP sessions. | separate P2P and P2MP LDP sessions. | |||
6.12. IPv4/IPv6 support | 4.12. IPv4/IPv6 Support | |||
The P2MP LDP mechanism MUST support the establishment of LDP sessions | The P2MP LDP mechanism MUST support the establishment of LDP sessions | |||
over both IPv4 and IPv6 control planes. | over both IPv4 and IPv6 control planes. | |||
6.13. Multi-Area/AS LSPs | 4.13. Multi-Area/AS LSPs | |||
The P2MP LDP mechanism MUST support the establishment of multi-area | The P2MP LDP mechanism MUST support the establishment of multi-area | |||
P2MP LSPs, i.e. LSPs whose leaves do not all reside in the same IGP | P2MP LSPs, i.e. LSPs whose leaves do not all reside in the same IGP | |||
area as the Ingress LSR. This SHOULD be possible without requiring | area as the Ingress LSR. This SHOULD be possible without requiring | |||
the advertisement of Ingress LSRs' addresses across IGP areas. | the advertisement of Ingress LSRs' addresses across IGP areas. | |||
The P2MP LDP mechanism MUST also support the establishment of | The P2MP LDP mechanism MUST also support the establishment of | |||
inter-AS P2MP LSPs, i.e. LSPs whose leaves do not all reside in the | inter-AS P2MP LSPs, i.e. LSPs whose leaves do not all reside in the | |||
same AS as the Ingress LSR. This SHOULD be possible without | same AS as the Ingress LSR. This SHOULD be possible without | |||
requiring the advertisement of Ingress LSRs' addresses across ASes. | requiring the advertisement of Ingress LSRs' addresses across ASes. | |||
6.14. OAM | 4.14. OAM | |||
LDP management tools ([RFC3815], etc.) will have to be enhanced to | LDP management tools ([RFC3815], etc.) will have to be enhanced to | |||
support P2MP LDP extensions. This may yield a new MIB module, which | support P2MP LDP extensions. This may yield a new MIB module, which | |||
may possibly be inherited from the LDP MIB. | may possibly be inherited from the LDP MIB. | |||
Built-in diagnostic tools MUST be defined to check the connectivity, | Built-in diagnostic tools MUST be defined to check the connectivity, | |||
trace the path and ensure fast detection of data plane failures on | trace the path and ensure fast detection of data plane failures on | |||
P2MP LDP LSPs. | P2MP LDP LSPs. | |||
Further and precise requirements and mechanisms for P2MP MPLS OAM | Further and precise requirements and mechanisms for P2MP MPLS OAM | |||
purpose are out of the scope of this document and are addressed in | purpose are out of the scope of this document and are addressed in | |||
[RFC4687]. | [RFC4687]. | |||
6.15. Graceful Restart and Fault Recovery | 4.15. Graceful Restart and Fault Recovery | |||
LDP Graceful Restart mechanisms [RFC3478] and Fault Recovery | LDP Graceful Restart mechanisms [RFC3478] and Fault Recovery | |||
mechanisms [RFC3479] SHOULD be enhanced to support P2MP LDP LSPs. | mechanisms [RFC3479] SHOULD be enhanced to support P2MP LDP LSPs. | |||
6.16. Robustness | 4.16. Robustness | |||
A solution MUST be designed to re-establish connectivity for P2MP and | A solution MUST be designed to re-establish connectivity for P2MP and | |||
MP2MP LSPs in the event of failures, provided there exists network | MP2MP LSPs in the event of failures, provided there exists network | |||
connectivity between ingress and egress nodes (i.e. designed without | connectivity between ingress and egress nodes (i.e. designed without | |||
introducing single points of failure). | introducing single points of failure). | |||
6.17. Scalability | 4.17. Scalability | |||
Scalability is a key requirement for the P2MP LDP mechanism. It MUST | Scalability is a key requirement for the P2MP LDP mechanism. It MUST | |||
be designed to scale well with an increase in the number of any of | be designed to scale well with an increase in the number of any of | |||
the following: | the following: | |||
o number of Leaf LSRs per P2MP LSP; | o number of Leaf LSRs per P2MP LSP; | |||
o number of Downstream LSRs per Branch LSR; | o number of Downstream LSRs per Branch LSR; | |||
o number of P2MP LSPs per LSR. | o number of P2MP LSPs per LSR. | |||
In order to scale well with an increase in the number of leaves, it | In order to scale well with an increase in the number of leaves, it | |||
is RECOMMENDED that the size of a P2MP LSP state on a LSR, for one | is RECOMMENDED that the size of a P2MP LSP state on a LSR, for one | |||
particular LSP, depend only on the number of adjacent LSRs on the | particular LSP, depend only on the number of adjacent LSRs on the | |||
LSP. | LSP. | |||
6.17.1. Orders of magnitude expected in operational networks | 4.17.1. Orders of Magnitude Expected in Operational Networks | |||
Typical orders of magnitude that we expect should be supported are: | Typical orders of magnitude that we expect should be supported are: | |||
o tens of thousands of P2MP trees spread out across core network | o tens of thousands of P2MP trees spread out across core network | |||
routers; | routers; | |||
o hundreds, or a few thousands, of leaves per tree; | o hundreds, or a few thousands, of leaves per tree; | |||
See also section 4.2 of [RFC4834]. | See also section 4.2 of [RFC4834]. | |||
6.18. Backward Compatibility | 4.18. Backward Compatibility | |||
In order to allow for a smooth migration, the P2MP LDP mechanism | In order to allow for a smooth migration, the P2MP LDP mechanism | |||
SHOULD offer as much backward compatibility as possible. In | SHOULD offer as much backward compatibility as possible. In | |||
particular, the solution SHOULD allow the setup of a P2MP LSP along | particular, the solution SHOULD allow the setup of a P2MP LSP along | |||
non-Branch Transit LSRs that do not support P2MP LDP extensions. | non-Branch Transit LSRs that do not support P2MP LDP extensions. | |||
Also, the P2MP LDP solution MUST co-exist with current LDP mechanisms | Also, the P2MP LDP solution MUST co-exist with current LDP mechanisms | |||
and inherit its capability sets from [RFC5036]. The P2MP LDP | and inherit its capability sets from [RFC5036]. The P2MP LDP | |||
solution MUST NOT impede the operation of P2P/MP2P LSPs. A P2MP LDP | solution MUST NOT impede the operation of P2P/MP2P LSPs. A P2MP LDP | |||
solution MUST be designed in such a way that it allows P2P/MP2P and | solution MUST be designed in such a way that it allows P2P/MP2P and | |||
P2MP LSPs to be signalled on the same interface. | P2MP LSPs to be signalled on the same interface. | |||
7. Shared Trees | 5. Shared Trees | |||
For traffic delivery between a group of N LSRs that act as egress | For traffic delivery between a group of N LSRs that act as egress | |||
and/or egress nodes on different P2MP flows, it may be useful to | and/or egress nodes on different P2MP flows, it may be useful to | |||
setup a shared tree connecting all these LSRs, instead of having N | setup a shared tree connecting all these LSRs, instead of having N | |||
P2MP LSPs. This would reduce the amount of control and forwarding | P2MP LSPs. This would reduce the amount of control and forwarding | |||
state that has to be maintained on a given LSR. | state that has to be maintained on a given LSR. | |||
There are actually two main options for supporting such shared trees: | There are actually two main options for supporting such shared trees: | |||
o This could rely on the applications protocols that use LDP LSPs. | o This could rely on the applications protocols that use LDP LSPs. | |||
skipping to change at page 15, line 18 | skipping to change at page 15, line 31 | |||
* with a P2MP LDP LSP from this root PE to each PE of the group. | * with a P2MP LDP LSP from this root PE to each PE of the group. | |||
o Or this could rely on a specific LDP mechanism allowing to setup | o Or this could rely on a specific LDP mechanism allowing to setup | |||
multipoint-to-multipoint MPLS LSPs (MP2MP LSPs). | multipoint-to-multipoint MPLS LSPs (MP2MP LSPs). | |||
The former approach (Combination of MP2P and P2MP LSPs at the | The former approach (Combination of MP2P and P2MP LSPs at the | |||
application level) is out of the scope of this document while the | application level) is out of the scope of this document while the | |||
latter (MP2MP LSPs) belong to the scope of this document. | latter (MP2MP LSPs) belong to the scope of this document. | |||
Requirements for the set up of MP2MP LSPs are listed below. | Requirements for the set up of MP2MP LSPs are listed below. | |||
7.1. Requirements for MP2MP LSPs | 5.1. Requirements for MP2MP LSPs | |||
A Multipoint-to-multipoint (MP2MP) LSP is an LSP connecting a group | A Multipoint-to-multipoint (MP2MP) LSP is an LSP connecting a group | |||
of Leaf LSRs acting as Egress and/or Ingress LSRs. Traffic sent by | of Leaf LSRs acting as Egress and/or Ingress LSRs. Traffic sent by | |||
any Leaf LSR is received by all other Leaf LSRs of the group. | any Leaf LSR is received by all other Leaf LSRs of the group. | |||
Procedures for setting up MP2MP LSPs with LDP SHOULD be specified. | Procedures for setting up MP2MP LSPs with LDP SHOULD be specified. | |||
An implementation that support P2MP LDP LSPs MAY also support MP2MP | An implementation that support P2MP LDP LSPs MAY also support MP2MP | |||
LDP LSP. | LDP LSP. | |||
The MP2MP LDP procedures MUST NOT impede the operations of P2MP LSP. | The MP2MP LDP procedures MUST NOT impede the operations of P2MP LSP. | |||
Requirements for P2MP LSPs, set forth in Section 6, apply equally to | Requirements for P2MP LSPs, set forth in Section 4, apply equally to | |||
MP2MP LSPs. Particular attention should be given on the below | MP2MP LSPs. Particular attention should be given on the below | |||
requirements: | requirements: | |||
o The solution MUST support recovery upon link and transit node | o The solution MUST support recovery upon link and transit node | |||
failure and be designed to re-establish connectivity for MP2MP | failure and be designed to re-establish connectivity for MP2MP | |||
LSPs in the event of failures, provided there exists network | LSPs in the event of failures, provided there exists network | |||
connectivity between ingress and egress nodes (i.e. designed | connectivity between ingress and egress nodes (i.e. designed | |||
without introducing single points of failure); | without introducing single points of failure); | |||
o The size of MP2MP state on a LSR, for one particular MP2MP LSP, | o The size of MP2MP state on a LSR, for one particular MP2MP LSP, | |||
skipping to change at page 16, line 19 | skipping to change at page 16, line 32 | |||
MP2MP LSP; | MP2MP LSP; | |||
o The solution SHOULD avoid that all traffic between any pair of | o The solution SHOULD avoid that all traffic between any pair of | |||
leaves is traversing a root LSR (similarly to PIM-Bidir trees) and | leaves is traversing a root LSR (similarly to PIM-Bidir trees) and | |||
SHOULD provide the operator with means to minimize the delay | SHOULD provide the operator with means to minimize the delay | |||
between two leaves; | between two leaves; | |||
o It MUST be possible to check connectivity of a MP2MP LSP in both | o It MUST be possible to check connectivity of a MP2MP LSP in both | |||
directions. | directions. | |||
8. Evaluation criteria | 6. Evaluation Criteria | |||
8.1. Performance | 6.1. Performance | |||
The solution will be evaluated with respect to the following | The solution will be evaluated with respect to the following | |||
criteria: | criteria: | |||
(1) Efficiency of network resource usage; | (1) Efficiency of network resource usage; | |||
(2) Time to add or remove a Leaf LSR; | (2) Time to add or remove a Leaf LSR; | |||
(3) Time to repair a P2MP LSP in case of link or node failure; | (3) Time to repair a P2MP LSP in case of link or node failure; | |||
(4) Scalability (state size, number of messages, message size). | (4) Scalability (state size, number of messages, message size). | |||
Particularly the P2MP LDP mechanism SHOULD be designed with as key | Particularly the P2MP LDP mechanism SHOULD be designed with as key | |||
objective to minimize the additional amount of state and additional | objective to minimize the additional amount of state and additional | |||
processing required in the network. | processing required in the network. | |||
Also, the P2MP LDP mechanism SHOULD be designed so that convergence | Also, the P2MP LDP mechanism SHOULD be designed so that convergence | |||
times in case of link or node failure are minimized, in order to | times in case of link or node failure are minimized, in order to | |||
limit traffic disruption. | limit traffic disruption. | |||
8.2. Complexity and Risks | 6.2. Complexity and Risks | |||
The proposed solution SHOULD NOT introduce complexity to the current | The proposed solution SHOULD NOT introduce complexity to the current | |||
LDP operations to such a degree that it would affect the stability | LDP operations to such a degree that it would affect the stability | |||
and diminish the benefits of deploying such solution. | and diminish the benefits of deploying such solution. | |||
9. Security Considerations | 7. Security Considerations | |||
It is expected that addressing the requirements defined in this | It is expected that addressing the requirements defined in this | |||
document should not introduce any new security issue beyond those | document should not introduce any new security issue beyond those | |||
inherent to LDP, and that a P2MP LDP solution will rely on the | inherent to LDP, and that a P2MP LDP solution will rely on the | |||
security mechanisms defined in [RFC5036] (e.g. TCP MD5 Signature). | security mechanisms defined in [RFC5036] (e.g. TCP MD5 Signature). | |||
An evaluation of the security features for MPLS networks may be found | An evaluation of the security features for MPLS networks may be found | |||
in [RFC5920], and where issues or further work is identified by that | in [RFC5920], and where issues or further work is identified by that | |||
document, new security features or procedures for the MPLS protocols | document, new security features or procedures for the MPLS protocols | |||
will need to be developed. | will need to be developed. | |||
10. IANA Considerations | 8. IANA Considerations | |||
This informational document makes no requests to IANA for action. | This informational document makes no requests to IANA for action. | |||
11. Acknowledgments | 9. Acknowledgments | |||
We would like to thank Christian Jacquenet, Hitoshi Fukuda, Ina | We would like to thank Christian Jacquenet, Hitoshi Fukuda, Ina | |||
Minei, Dean Cheng, and Benjamin Niven-Jenkins, for their highly | Minei, Dean Cheng, and Benjamin Niven-Jenkins, for their highly | |||
useful comments and suggestions. We would also like to thank Adrian | useful comments and suggestions. We would also like to thank Adrian | |||
Farrel for reviewing this document before publication. | Farrel for reviewing this document before publication. | |||
We would also like to thank authors of [RFC4461] from which some of | We would also like to thank authors of [RFC4461] from which some of | |||
the text in this document has been inspired. | the text in this document has been inspired. | |||
12. References | 10. References | |||
12.1. Normative References | 10.1. Normative References | |||
[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. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[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. | |||
[RFC3478] Leelanivas, M., Rekhter, Y., and R. Aggarwal, "Graceful | [RFC3478] Leelanivas, M., Rekhter, Y., and R. Aggarwal, "Graceful | |||
Restart Mechanism for Label Distribution Protocol", | Restart Mechanism for Label Distribution Protocol", | |||
RFC 3478, February 2003. | RFC 3478, February 2003. | |||
skipping to change at page 18, line 12 | skipping to change at page 18, line 24 | |||
(MPLS), Label Distribution Protocol (LDP)", RFC 3815, | (MPLS), Label Distribution Protocol (LDP)", RFC 3815, | |||
June 2004. | June 2004. | |||
[RFC4461] Yasukawa, S., "Signaling Requirements for Point-to- | [RFC4461] Yasukawa, S., "Signaling Requirements for Point-to- | |||
Multipoint Traffic-Engineered MPLS Label Switched Paths | Multipoint Traffic-Engineered MPLS Label Switched Paths | |||
(LSPs)", RFC 4461, April 2006. | (LSPs)", RFC 4461, April 2006. | |||
[RFC5036] Andersson, L., Minei, I., and B. Thomas, "LDP | [RFC5036] Andersson, L., Minei, I., and B. Thomas, "LDP | |||
Specification", RFC 5036, October 2007. | Specification", RFC 5036, October 2007. | |||
12.2. Informative References | 10.2. Informative References | |||
[I-D.ietf-l2vpn-vpls-mcast] | [I-D.ietf-l2vpn-vpls-mcast] | |||
Aggarwal, R., Kamite, Y., Fang, L., and Y. Rekhter, | Aggarwal, R., Kamite, Y., Fang, L., and Y. Rekhter, | |||
"Multicast in VPLS", draft-ietf-l2vpn-vpls-mcast-08 (work | "Multicast in VPLS", draft-ietf-l2vpn-vpls-mcast-08 (work | |||
in progress), October 2010. | in progress), October 2010. | |||
[I-D.ietf-l3vpn-2547bis-mcast] | [I-D.ietf-l3vpn-2547bis-mcast] | |||
Aggarwal, R., Bandi, S., Cai, Y., Morin, T., Rekhter, Y., | Aggarwal, R., Bandi, S., Cai, Y., Morin, T., Rekhter, Y., | |||
Rosen, E., Wijnands, I., and S. Yasukawa, "Multicast in | Rosen, E., Wijnands, I., and S. Yasukawa, "Multicast in | |||
MPLS/BGP IP VPNs", draft-ietf-l3vpn-2547bis-mcast-10 (work | MPLS/BGP IP VPNs", draft-ietf-l3vpn-2547bis-mcast-10 (work | |||
End of changes. 60 change blocks. | ||||
115 lines changed or deleted | 127 lines changed or added | |||
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