draft-ietf-mpls-rsvp-egress-protection-01.txt   draft-ietf-mpls-rsvp-egress-protection-02.txt 
Internet Engineering Task Force H. Chen Internet Engineering Task Force H. Chen
Internet-Draft Z. Li Internet-Draft Z. Li
Intended status: Standards Track Huawei Technologies Intended status: Standards Track Huawei Technologies
Expires: January 4, 2015 N. So Expires: April 29, 2015 N. So
Tata Communications Tata Communications
A. Liu A. Liu
Ericsson Ericsson
T. Saad
Cisco Systems
F. Xu F. Xu
Verizon Verizon
M. Toy M. Toy
Comcast Comcast
L. Huang L. Huang
China Mobile China Mobile
L. Liu L. Liu
UC Davis UC Davis
July 3, 2014 October 26, 2014
Extensions to RSVP-TE for LSP Egress Local Protection Extensions to RSVP-TE for LSP Egress Local Protection
draft-ietf-mpls-rsvp-egress-protection-01.txt draft-ietf-mpls-rsvp-egress-protection-02.txt
Abstract Abstract
This document describes extensions to Resource Reservation Protocol - This document describes extensions to Resource Reservation Protocol -
Traffic Engineering (RSVP-TE) for locally protecting egress nodes of Traffic Engineering (RSVP-TE) for locally protecting egress nodes of
a Traffic Engineered (TE) Label Switched Path (LSP) in a Multi- a Traffic Engineered (TE) Label Switched Path (LSP) in a Multi-
Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) network. Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) network.
Status of this Memo Status of this Memo
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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 January 4, 2015. This Internet-Draft will expire on April 29, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. An Example of Egress Local Protection . . . . . . . . . . 3 1.1. An Example of Egress Local Protection . . . . . . . . . . 3
1.2. Egress Local Protection with FRR . . . . . . . . . . . . . 4 1.2. Egress Local Protection with FRR . . . . . . . . . . . . . 4
2. Conventions Used in This Document . . . . . . . . . . . . . . 4 2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 4 4. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 4
4.1. EGRESS_BACKUP Object . . . . . . . . . . . . . . . . . . . 4 4.1. EGRESS_BACKUP Object . . . . . . . . . . . . . . . . . . . 4
4.2. Flags in FAST_REROUTE . . . . . . . . . . . . . . . . . . 6 4.2. Flags in FAST_REROUTE . . . . . . . . . . . . . . . . . . 6
4.3. Path Message . . . . . . . . . . . . . . . . . . . . . . . 6 4.3. Path Message . . . . . . . . . . . . . . . . . . . . . . . 6
5. Egress Protection Behaviors . . . . . . . . . . . . . . . . . 6 5. Egress Protection Behaviors . . . . . . . . . . . . . . . . . 6
5.1. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 6 5.1. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 7
5.2. Intermediate Node and PLR Behavior . . . . . . . . . . . . 7 5.2. Transit Node and PLR Behavior . . . . . . . . . . . . . . 7
5.2.1. Signaling for One-to-One Protection . . . . . . . . . 8 5.2.1. Signaling for One-to-One Protection . . . . . . . . . 8
5.2.2. Signaling for Facility Protection . . . . . . . . . . 8 5.2.2. Signaling for Facility Protection . . . . . . . . . . 8
5.2.3. Signaling for S2L Sub LSP Protection . . . . . . . . . 9 5.2.3. Signaling for S2L Sub LSP Protection . . . . . . . . . 9
5.2.4. PLR Procedures during Local Repair . . . . . . . . . . 10 5.2.4. PLR Procedures during Local Repair . . . . . . . . . . 10
6. Considering Application Traffic . . . . . . . . . . . . . . . 10 6. Considering Application Traffic . . . . . . . . . . . . . . . 10
6.1. A Typical Application . . . . . . . . . . . . . . . . . . 10 6.1. A Typical Application . . . . . . . . . . . . . . . . . . 10
6.2. PLR Procedure for Applications . . . . . . . . . . . . . . 11 6.2. PLR Procedure for Applications . . . . . . . . . . . . . . 11
6.3. Egress Procedures for Applications . . . . . . . . . . . . 11 6.3. Egress Procedures for Applications . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. New RSVP C-Num and C-Types . . . . . . . . . . . . . . . . 12
8.2. New TLVs . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.3. Flags in FAST_REROUTE . . . . . . . . . . . . . . . . . . 13
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 13 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 13
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
11.1. Normative References . . . . . . . . . . . . . . . . . . . 13 11.1. Normative References . . . . . . . . . . . . . . . . . . . 13
11.2. Informative References . . . . . . . . . . . . . . . . . . 14 11.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
RFC 4090 describes two methods for protecting the transit nodes of a RFC 4090 describes two methods for protecting the transit nodes of a
P2P LSP: one-to-one and facility protection. RFC 4875 specifies how P2P LSP: one-to-one and facility protection. RFC 4875 specifies how
to use them to protect the transit nodes of a P2MP LSP. However, to use them to protect the transit nodes of a P2MP LSP. However,
they do not mention any local protection for an egress of an LSP. they do not mention any local protection for an egress of an LSP.
To protect the egresses of an LSP (P2P or P2MP), an existing approach To protect the egresses of an LSP (P2P or P2MP), an existing approach
sets up a backup LSP from a backup ingress (or the ingress of the sets up a backup LSP from a backup ingress (or the ingress of the
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The time for switching the traffic is within tens of milliseconds. The time for switching the traffic is within tens of milliseconds.
The failure of a primary egress (e.g., L1 in the figure) MAY be The failure of a primary egress (e.g., L1 in the figure) MAY be
detected by its upstream node (e.g., R3 in the figure) through a BFD detected by its upstream node (e.g., R3 in the figure) through a BFD
between the upstream node and the egress in MPLS networks. Exactly between the upstream node and the egress in MPLS networks. Exactly
how the failure is detected is out of scope for this document. how the failure is detected is out of scope for this document.
1.2. Egress Local Protection with FRR 1.2. Egress Local Protection with FRR
Using the egress local protection and the FRR, we can locally protect Using the egress local protection and the FRR, we can locally protect
the egresses, the links and the intermediate nodes of an LSP. The the egresses, the links and the transit nodes of an LSP. The traffic
traffic switchover time is within tens of milliseconds whenever an switchover time is within tens of milliseconds whenever an egress,
egress, any of the links and the intermediate nodes of the LSP fails. any of the links and the transit nodes of the LSP fails.
The egress nodes of the LSP can be locally protected via the egress The egress nodes of the LSP can be locally protected via the egress
local protection. All the links and the intermediate nodes of the local protection. All the links and the transit nodes of the LSP can
LSP can be locally protected through using the FRR. be locally protected through using the FRR.
2. Conventions Used in This Document 2. 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. document are to be interpreted as described in RFC 2119.
3. Terminology 3. Terminology
This document uses terminologies defined in RFC 2205, RFC 3031, RFC This document uses terminologies defined in RFC 2205, RFC 3031, RFC
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~ Primary Egress IPv4/IPv6 address ~ ~ Primary Egress IPv4/IPv6 address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ (Subobjects) ~ ~ (Subobjects) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o Backup Egress IPv4/IPv6 address: o Backup Egress IPv4/IPv6 address:
IPv4/IPv6 address of the backup egress node IPv4/IPv6 address of the backup egress node
o Primary Egress IPv4/IPv6 address: o Primary Egress IPv4/IPv6 address:
IPv4/IPv6 address of the primary egress node IPv4/IPv6 address of the primary egress node
The Subobjects are optional. One of them is P2P LSP ID IPv4/IPv6 The Subobjects are TLVs and optional. One of them is P2P LSP ID
subobject, whose body has the following format and Type is TBD-4/ IPv4/IPv6 subobject, whose body has the following format and Type is
TBD-5. It may be used to identify a backup LSP. TBD-4/TBD-5. It may be used to identify a backup LSP.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ P2P LSP Tunnel Egress IPv4/IPv6 Address (4/16 bytes) ~ ~ P2P LSP Tunnel Egress IPv4/IPv6 Address (4/16 bytes) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Tunnel ID | | Reserved | Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Extended Tunnel ID (4/16 bytes) ~ ~ Extended Tunnel ID (4/16 bytes) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o P2P LSP Tunnel Egress IPv4/IPv6 Address: o P2P LSP Tunnel Egress IPv4/IPv6 Address:
IPv4/IPv6 address of the egress of the tunnel IPv4/IPv6 address of the egress of the tunnel
o Tunnel ID: o Tunnel ID:
A 16-bit identifier that is constant over the life of the tunnel A 16-bit identifier that is constant over the life of the tunnel
o Extended Tunnel ID: o Extended Tunnel ID:
A 4/16-byte identifier being constant over the life of the tunnel A 4/16-byte identifier being constant over the life of the tunnel
Another one is Label subobject, whose body has the format below and Another one is Label subobject, whose body has the format below and
Type is TBD-6 to be assigned by IANA. Type is TBD-6 to be assigned by IANA.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label | | Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ (sub-TLVs ) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The sub-TLVs are optional.
4.2. Flags in FAST_REROUTE 4.2. Flags in FAST_REROUTE
A bit of the flags in the FAST_REROUTE object may be used to indicate Two new bits of the flags in the FAST_REROUTE object may be defined.
whether S2L Sub LSP is desired for protecting an egress of a P2MP LSP One bit (called "S2L Sub LSP Backup Desired" flag) indicates whether
or One-to-One Backup is preferred for protecting an egress of a P2P S2L Sub LSP is desired for protecting an egress of a P2MP LSP. When
LSP when the "Facility Backup Desired" flag is set. This bit is a S2L Sub LSP is desired for protecting an egress of a P2MP LSP, we
called "S2L Sub LSP Backup Desired" or "One-to-One Backup Preferred". should set this flag to one.
The other bit (called "Other Sending UA Label" flag) indicates if
another protocol is desired for sending a label as a UA label from a
primary egress to a backup egress. When we want other protocol such
as BGP to send a label as UA label, this flag should be set to one.
4.3. Path Message 4.3. Path Message
A Path message is enhanced to carry the information about a backup A Path message is enhanced to carry the information about a backup
egress for a primary egress of an LSP through including an egress egress for a primary egress of an LSP by including an egress backup
backup descriptor list. The format of the enhanced Path message is descriptor list. The format of the message is illustrated below.
illustrated below.
<Path Message> ::= <Common Header> [ <INTEGRITY> ] <Path Message> ::= <Common Header> [ <INTEGRITY> ]
[ [<MESSAGE_ID_ACK> | <MESSAGE_ID_NACK>] ...] [ [<MESSAGE_ID_ACK> | <MESSAGE_ID_NACK>] ...]
[ <MESSAGE_ID> ]<SESSION> <RSVP_HOP> <TIME_VALUES> [ <MESSAGE_ID> ]<SESSION> <RSVP_HOP> <TIME_VALUES>
[ <EXPLICIT_ROUTE> ] [ <EXPLICIT_ROUTE> ]
<LABEL_REQUEST> [ <PROTECTION> ] [ <LABEL_SET> ...] <LABEL_REQUEST> [ <PROTECTION> ] [ <LABEL_SET> ...]
[ <SESSION_ATTRIBUTE> ] [ <NOTIFY_REQUEST> ] [ <SESSION_ATTRIBUTE> ] [ <NOTIFY_REQUEST> ]
[ <ADMIN_STATUS> ] [ <POLICY_DATA> ... ] [ <ADMIN_STATUS> ] [ <POLICY_DATA> ... ]
<sender descriptor> [<S2L sub-LSP descriptor list>] <sender descriptor> [<S2L sub-LSP descriptor list>]
[<egress backup descriptor list>] [<egress backup descriptor list>]
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If one-to-one backup or facility backup method is desired to protect If one-to-one backup or facility backup method is desired to protect
a primary egress of an LSP, the ingress SHOULD include a FAST_REROUTE a primary egress of an LSP, the ingress SHOULD include a FAST_REROUTE
object and set the "One-to-One Backup Desired" or "Facility Backup object and set the "One-to-One Backup Desired" or "Facility Backup
Desired" flag. Desired" flag.
If S2L Sub LSP backup method is desired to protect a primary egress If S2L Sub LSP backup method is desired to protect a primary egress
of a P2MP LSP, the ingress SHOULD include a FAST_REROUTE object and of a P2MP LSP, the ingress SHOULD include a FAST_REROUTE object and
set the "S2L Sub LSP Backup Desired" flag. set the "S2L Sub LSP Backup Desired" flag.
Note that if "Facility Backup Desired" flag is set for protecting the If another protocol is desired for sending a label as a upstream
intermediate nodes of a primary P2P LSP, but we want to use "One-to- assigned label to a backup egress, the ingress SHOULD set the "Other
One Backup" for protecting the egress of the LSP, then the ingress Sending UA Label" flag.
SHOULD set "One-to-One Backup Preferred" flag.
Optionally, a backup egress may be configured on the ingress of an Optionally, a backup egress may be configured on the ingress of an
LSP to protect a primary egress of the LSP. LSP to protect a primary egress of the LSP.
The ingress sends a Path message for the LSP with the objects above The ingress sends a Path message for the LSP with the objects above
and an optional egress backup descriptor list. For each primary and an optional egress backup descriptor list. For each primary
egress of the LSP to be protected, the ingress adds an EGRESS_BACKUP egress of the LSP to be protected, the ingress adds an EGRESS_BACKUP
object into the list if the backup egress is given. The object object into the list if the backup egress is given. The object
contains the primary egress and the backup egress for protecting the contains the primary egress and the backup egress for protecting the
primary egress. primary egress.
5.2. Intermediate Node and PLR Behavior 5.2. Transit Node and PLR Behavior
If an intermediate node of an LSP receives the Path message with an If a transit node of an LSP receives the Path message with an egress
egress backup descriptor list and it is not an upstream node of any backup descriptor list and it is not an upstream node of any primary
primary egress of the LSP, it forwards the list unchanged. egress of the LSP, it forwards the list unchanged.
If the intermediate node is the upstream node of a primary egress to If the transit node is the upstream node of a primary egress to be
be protected, it determines the backup egress, obtains a path for the protected, it determines the backup egress, obtains a path for the
backup LSP and sets up the backup LSP along the path. backup LSP and sets up the backup LSP along the path.
The PLR (upstream node of the primary egress) tries to get the backup The PLR (upstream node of the primary egress) extracts the backup
egress from EGRESS_BACKUP in the egress backup descriptor list if the egress from the respective EGRESS_BACKUP object in the egress backup
Path message contains the list. If the PLR can not get it, the PLR descriptor list. If no matching EGRESS_BACKUP object is found or the
tries to find the backup egress, which is not the primary egress but list is empty, the PLR may apply a local policy to determine the
has the same IP address as the destination IP address of the LSP. backup egress and add an EGRESS_BACKUP object with the backup egress
and primary egress into a Path message to the primary egress.
Note that the primary egress and the backup egress SHOULD have a same
local address configured, and the cost to the local address on the
backup egress SHOULD be much bigger than the cost to the local
address on the primary egress. Thus another name such as virtual
node based egress protection may be used for egress local protection.
After obtaining the backup egress, the PLR tries to compute a backup After obtaining the backup egress, the PLR tries to compute a backup
path from itself to the backup egress. It excludes the primary path from itself to the backup egress. It excludes the primary
egress to be protected when computing the path. Thus the PLR will egress to be protected when computing the path. Thus the PLR will
not select any path via the primary egress. not select any path via the primary egress.
The PLR then sets up the backup LSP along the path obtained. It The PLR then sets up the backup LSP along the path obtained. It
provides one-to-one backup protection for the primary egress if the provides one-to-one backup protection for the primary egress if the
"One-to-One Backup Desired" or "One-to-One Backup Preferred" flag is "One-to-One Backup Desired" flag is set in the message; otherwise, it
set in the message; otherwise, it provides facility backup protection provides facility backup protection if the "Facility Backup Desired
if the "Facility Backup Desired flag" is set. flag" is set.
The PLR sets the protection flags in the RRO Sub-object for the The PLR sets the protection flags in the RRO Sub-object for the
primary egress in the Resv message according to the status of the primary egress in the Resv message according to the status of the
primary egress and the backup LSP protecting the primary egress. For primary egress and the backup LSP protecting the primary egress. For
example, it will set the "local protection available" and the "node example, it will set the "local protection available" and the "node
protection" flag indicating that the primary egress is protected when protection" flag indicating that the primary egress is protected when
the backup LSP is up and ready for protecting the primary egress. the backup LSP is up and ready for protecting the primary egress.
5.2.1. Signaling for One-to-One Protection 5.2.1. Signaling for One-to-One Protection
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egress. If there is a backup LSP that satisfies the constraints egress. If there is a backup LSP that satisfies the constraints
given in the Path message, then this one is selected; otherwise, a given in the Path message, then this one is selected; otherwise, a
new backup LSP to the backup egress will be created. new backup LSP to the backup egress will be created.
After getting the backup LSP, the PLR associates the backup LSP with After getting the backup LSP, the PLR associates the backup LSP with
a primary LSP for protecting its primary egress. The PLR records a primary LSP for protecting its primary egress. The PLR records
that the backup LSP is used to protect the primary LSP against its that the backup LSP is used to protect the primary LSP against its
primary egress failure and includes an EGRESS_BACKUP object in the primary egress failure and includes an EGRESS_BACKUP object in the
Path message to the primary egress. The object contains the backup Path message to the primary egress. The object contains the backup
egress and the backup LSP ID. It indicates that the primary egress egress and the backup LSP ID. It indicates that the primary egress
SHOULD send the backup egress the primary LSP label as UA label. SHOULD send the backup egress the service label as UA label if there
is a service carried by the LSP and the primary LSP label as UA label
if the label is not implicit null.
A UA label can be sent via RSVP or another protocol (e.g., BGP). If
"Other Sending UA Label" flag is one, the primary egress SHOULD send
the UA labels to the backup egress through another protocol;
otherwise, UA labels are sent via RSVP.
After receiving the Path message with the EGRESS_BACKUP, the primary After receiving the Path message with the EGRESS_BACKUP, the primary
egress includes the information about the primary LSP label in the egress includes the information about the UA labels in the Resv
Resv message with an EGRESS_BACKUP object as UA label. When the PLR message with an EGRESS_BACKUP object. When the PLR receives the Resv
receives the Resv message with the information about the UA label, it message with the information about the UA labels, it includes the
includes the information in the Path message for the backup LSP to information in the Path message for the backup LSP to the backup
the backup egress. Thus the primary LSP label as UA label is sent to egress. Thus the UA labels are sent to the backup egress from the
the backup egress from the primary egress. primary egress via RSVP.
When the PLR detects the failure of the primary egress, it redirects When the PLR detects the failure of the primary egress, it redirects
the packets from the primary LSP into the backup LSP to backup egress the packets from the primary LSP into the backup LSP to backup egress
using the primary LSP label from the primary egress as an inner and keeps the primary LSP label from the primary egress in the label
label. The backup egress delivers the packets to the same stack if the label is not implicit null. The backup egress delivers
destinations as the primary egress using the backup LSP label as the packets to the same destinations as the primary egress using the
context label and the inner label as UA label. backup LSP label as context label and the labels under as UA labels.
5.2.3. Signaling for S2L Sub LSP Protection 5.2.3. Signaling for S2L Sub LSP Protection
The S2L Sub LSP Protection is used to protect a primary egress of a The S2L Sub LSP Protection is used to protect a primary egress of a
P2MP LSP. Its major advantage is that the application traffic P2MP LSP. Its major advantage is that the application traffic
carried by the LSP is easily protected against the egress failure. carried by the LSP is easily protected against the egress failure.
The PLR determines to protect a primary egress of a P2MP LSP via S2L The PLR determines to protect a primary egress of a P2MP LSP via S2L
sub LSP protection when it receives a Path message with flag "S2L Sub sub LSP protection when it receives a Path message with flag "S2L Sub
LSP Backup Desired" set. LSP Backup Desired" set.
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the forwarding entry for the backup LSP to active. Thus, the PLR the forwarding entry for the backup LSP to active. Thus, the PLR
forwards the traffic to the backup egress through the backup LSP, forwards the traffic to the backup egress through the backup LSP,
which sends the traffic to its destination. which sends the traffic to its destination.
5.2.4. PLR Procedures during Local Repair 5.2.4. PLR Procedures during Local Repair
When the upstream node of a primary egress of an LSP as a PLR detects When the upstream node of a primary egress of an LSP as a PLR detects
the failure of the primary egress, it follows the procedures defined the failure of the primary egress, it follows the procedures defined
in section 6.5 of RFC 4090. It SHOULD notify the ingress about the in section 6.5 of RFC 4090. It SHOULD notify the ingress about the
failure of the primary egress in the same way as a PLR notifies the failure of the primary egress in the same way as a PLR notifies the
ingress about the failure of an intermediate node. ingress about the failure of a transit node.
Moreover, the PLR lets the upstream part of the primary LSP stay Moreover, the PLR lets the upstream part of the primary LSP stay
after the primary egress fails. It continues to send resv message to after the primary egress fails. It continues to send Resv message to
its upstream node along the primary LSP. The downstream part of the its upstream node along the primary LSP. The downstream part of the
primary LSP from the PLR to the primary egress SHOULD be removed. primary LSP from the PLR to the primary egress SHOULD be removed.
In the local revertive mode, the PLR re-signals each of the primary In the local revertive mode, the PLR re-signals each of the primary
LSPs that were routed over the restored resource once it detects that LSPs that were routed over the restored resource once it detects that
the resource is restored. Every primary LSP successfully re-signaled the resource is restored. Every primary LSP successfully re-signaled
along the restored resource is switched back. along the restored resource is switched back.
6. Considering Application Traffic 6. Considering Application Traffic
skipping to change at page 11, line 48 skipping to change at page 12, line 11
protecting a primary egress of a primary LSP, it includes an protecting a primary egress of a primary LSP, it includes an
EGRESS_BACKUP object in the Path message for the primary LSP. The EGRESS_BACKUP object in the Path message for the primary LSP. The
object contains the ID information of the backup LSP and indicates object contains the ID information of the backup LSP and indicates
that the primary egress SHOULD send the backup egress the application that the primary egress SHOULD send the backup egress the application
traffic label (e.g., VPN label) as UA label when needed. traffic label (e.g., VPN label) as UA label when needed.
6.3. Egress Procedures for Applications 6.3. Egress Procedures for Applications
When a primary egress of an LSP sends the ingress of the LSP a label When a primary egress of an LSP sends the ingress of the LSP a label
for an application such as a VPN, it SHOULD send the backup egress for an application such as a VPN, it SHOULD send the backup egress
for protecting the primary egress the label as a UA label via BGP or for protecting the primary egress the label as a UA label. Exactly
another protocol. Exactly how the label is sent is out of scope for how the label is sent is out of scope for this document.
this document.
When the backup egress receives a UA label from the primary egress, When the backup egress receives a UA label from the primary egress,
it adds a forwarding entry with the label into the LFIB for the it adds a forwarding entry with the label into the LFIB for the
primary egress. When the backup egress receives a packet from the primary egress. When the backup egress receives a packet from the
backup LSP, it uses the top label as a context label to find the LFIB backup LSP, it uses the top label as a context label to find the LFIB
for the primary egress and the inner label to deliver the packet to for the primary egress and the inner label to deliver the packet to
the same destination as the primary egress according to the LFIB. the same destination as the primary egress according to the LFIB.
7. Security Considerations 7. Security Considerations
In principle this document does not introduce new security issues. In principle this document does not introduce new security issues.
The security considerations pertaining to RFC 4090, RFC 4875 and The security considerations pertaining to RFC 4090, RFC 4875 and
other RSVP protocols remain relevant. other RSVP protocols remain relevant.
8. IANA Considerations 8. IANA Considerations
IANA considerations for new objects will be specified after the 8.1. New RSVP C-Num and C-Types
objects used are decided upon.
This document defines a new C-Num, which should be assigned by IANA.
o EGRESS_BACKUP object. The C-Num should be of the form 11bbbbbb so
that LSRs that do not recognize it will ignore it but forward it.
Two C-Types defined for this object should be assigned by IANA.
- EGRESS_BACKUP_IPv4. Recommended C-Type value 1.
- EGRESS_BACKUP_IPv6. Recommended C-Type value 2.
8.2. New TLVs
The new object referenced above contains TLVs. This document defines
three TLV types as follows:
Type Name Allowed on
1 P2P_LSP_ID_IPv4 TLV EGRESS_BACKUP_IPv4
2 P2P_LSP_ID_IPv6 TLV EGRESS_BACKUP_IPv6
3 Label TLV EGRESS_BACKUP_IPv4/IPv6
8.3. Flags in FAST_REROUTE
Two flags defined in FAST_REROUTE object should be assigned by IANA.
0x04 S2L Sub LSP Backup Desired
0x08 Other Sending UA Label
9. Contributors 9. Contributors
Boris Zhang Boris Zhang
Telus Communications Telus Communications
200 Consilium Pl Floor 15 200 Consilium Pl Floor 15
Toronto, ON M1H 3J3 Toronto, ON M1H 3J3
Canada Canada
Email: Boris.Zhang@telus.com Email: Boris.Zhang@telus.com
skipping to change at page 13, line 7 skipping to change at page 13, line 37
Vic Liu Vic Liu
China Mobile China Mobile
No.32 Xuanwumen West Street, Xicheng District No.32 Xuanwumen West Street, Xicheng District
Beijing, 100053 Beijing, 100053
China China
Email: liuzhiheng@chinamobile.com Email: liuzhiheng@chinamobile.com
10. Acknowledgement 10. Acknowledgement
The authors would like to thank Richard Li, Nobo Akiya, Tarek Saad, The authors would like to thank Richard Li, Nobo Akiya, Jeffrey
Lizhong Jin, Ravi Torvi, Eric Gray, Olufemi Komolafe, Michael Yue, Zhang, Lizhong Jin, Ravi Torvi, Eric Gray, Olufemi Komolafe, Michael
Rob Rennison, Neil Harrison, Kannan Sampath, Yimin Shen, Ronhazli Yue, Daniel King, Rob Rennison, Neil Harrison, Kannan Sampath, Yimin
Adam and Quintin Zhao for their valuable comments and suggestions on Shen, Ronhazli Adam and Quintin Zhao for their valuable comments and
this draft. suggestions on this draft.
11. References 11. References
11.1. Normative References 11.1. 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.
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004. Considered Useful", BCP 82, RFC 3692, January 2004.
skipping to change at page 15, line 4 skipping to change at page 15, line 29
Email: lizhenbin@huawei.com Email: lizhenbin@huawei.com
Ning So Ning So
Tata Communications Tata Communications
2613 Fairbourne Cir. 2613 Fairbourne Cir.
Plano, TX 75082 Plano, TX 75082
USA USA
Email: ningso01@gmail.com Email: ningso01@gmail.com
Autumn Liu Autumn Liu
Ericsson Ericsson
CA CA
USA USA
Email: autumn.liu@ericsson.com Email: autumn.liu@ericsson.com
Tarek Saad
Cisco Systems
Email: tsaad@cisco.com
Fengman Xu Fengman Xu
Verizon Verizon
2400 N. Glenville Dr 2400 N. Glenville Dr
Richardson, TX 75082 Richardson, TX 75082
USA USA
Email: fengman.xu@verizon.com Email: fengman.xu@verizon.com
Mehmet Toy Mehmet Toy
Comcast Comcast
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