MPLS Working Group M. Taillon
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track T. Saad, Ed.
Expires: November 3, 2019 Juniper Networks
R. Gandhi
Cisco Systems, Inc.
A. Deshmukh
Juniper Networks
M. Jork
128 Technology
V. Beeram
Juniper Networks
May 02, 2019
RSVP-TE Summary Fast Reroute Extensions for LSP Tunnels
draft-ietf-mpls-summary-frr-rsvpte-03
Abstract
This document defines Resource Reservation Protocol (RSVP) Traffic-
Engineering (TE) signaling extensions that reduce the amount of RSVP
signaling required for Fast Reroute (FRR) procedures and subsequently
improve the scalability of the RSVP-TE signaling when undergoing FRR
convergence after a link or node failure. Such extensions allow the
RSVP message exchange between the Point of Local Repair (PLR) and the
Merge Point (MP) to be independent of the number of protected Label
Switched Paths (LSPs) traversing between them when facility bypass
FRR protection is used. The signaling extensions are fully backwards
compatible with nodes that do not support them.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 3, 2019.
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Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Acronyms and Abbreviations . . . . . . . . . . . . . . . 4
3. Extensions for Summary FRR Signaling . . . . . . . . . . . . 4
3.1. B-SFRR-Ready Extended ASSOCIATION Object . . . . . . . . 5
3.1.1. IPv4 B-SFRR-Ready IPv4 Extended ASSOCIATION ID . . . 6
3.1.2. IPv6 B-SFRR-Ready IPv6 Extended ASSOCIATION ID . . . 7
3.2. B-SFRR-Active Extended ASSOCIATION Object . . . . . . . . 10
3.2.1. B-SFRR-Active Extended ASSOCIATION ID . . . . . . . . 11
3.3. Signaling Procedures Prior to Failure . . . . . . . . . . 12
3.3.1. PLR Signaling Procedure . . . . . . . . . . . . . . . 12
3.3.2. MP Signaling Procedure . . . . . . . . . . . . . . . 12
3.4. Signaling Procedures Post Failure . . . . . . . . . . . . 13
3.4.1. PLR Signaling Procedure . . . . . . . . . . . . . . . 13
3.4.2. MP Signaling Procedure . . . . . . . . . . . . . . . 14
3.5. Refreshing Summary FRR Active LSPs . . . . . . . . . . . 15
4. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
9.1. Normative References . . . . . . . . . . . . . . . . . . 16
9.2. Informative References . . . . . . . . . . . . . . . . . 17
9.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
The Fast Reroute (FRR) procedures defined in [RFC4090] describe the
mechanisms for the Point of Local Repair (PLR) to reroute traffic and
signaling of a protected RSVP-TE LSP onto the bypass tunnel in the
event of a TE link or node failure. Such signaling procedures are
performed individually for each affected protected LSP. This may
eventually lead to control plane scalability and latency issues on
the PLR and/or the MP due to limited memory and CPU processing
resources. This condition is exacerbated when the failure affects
large number of protected LSPs that traverse the same PLR and Merge
Point (MP) nodes.
For example, in a large scale RSVP-TE LSPs deployment, a single LSR
acting as a PLR node may host tens of thousands of protected RSVP-TE
LSPs egressing the same link, and also act as a MP node for similar
number of LSPs ingressing the same link. In the event of the failure
of the link or neighbor node, the RSVP-TE control plane of the node
when acting as PLR becomes busy rerouting protected LSPs signaling
over the bypass tunnel(s) in one direction, and when acting as an MP
node becomes busy merging RSVP states from signaling received over
bypass tunnels for LSP(s) in the reverse direction. Subsequently,
the head-end LER(s) that are notified of the local repair at
downstream LSR will attempt to (re)converge affected RSVP- TE LSPs
onto newly computed paths - possibly traversing the same previously
affected LSR(s). As a result, the RSVP-TE control plane at the PLR
and MP becomes overwhelmed by the amount of FRR RSVP-TE processing
overhead following the link or node failure, and the competing other
control plane protocol(s) (e.g. the IGP) that undergo their
convergence at the same time.
The extensions defined in this document enable a MP node to become
aware of the PLR node's bypass tunnel assignment group and allow FRR
procedures between PLR node and MP node to be signaled and processed
on groups of LSPs.
As defined in [RFC2961], Summary Refresh procedures use MESSAGE_ID to
refresh the RSVP Path and Resv states to help with the scale. The
MESSAGE_ID information for the rerouted PATH and RESV states are
exchanged between PLR and MP nodes between PLR and MP nodes a priori
to the fault such that Summary Refresh procedures defined in
[RFC2961] can continue to be used to refresh the rerouted state(s)
after FRR has occurred.
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2. Conventions Used in This Document
2.1. Terminology
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 BCP 14, RFC 2119
[RFC2119].
2.2. Acronyms and Abbreviations
The reader is assumed to be familiar with terms and abbreviations
used in [RFC3209] and [RFC4090].
The following abbreviations are also used in this document:
LSR: Label Switching Router
LER: Label Edge Router
MPLS: Multiprotocol Label Switching
LSP: Label Switched Path
MP: Merge Point node as defined in [RFC4090]
PLR: Point of Local Repair node as defined in [RFC4090]
FRR: Fast Reroute as defined in [RFC4090]
B-SFRR-Ready: Bypass Summary FRR Ready Extended ASSOCIATION
object. Added by the PLR for each LSP protected by the bypass
tunnel.
B-SFRR-Active: Bypass Summary FRR Active Extended ASSOCIATION
object. Used to notify the MP node of one ore more groups of
protected LSP(s) that are being protected by the specified bypass
tunnel are being rerouted.
3. Extensions for Summary FRR Signaling
The RSVP ASSOCIATION object is defined in [RFC4872] as a means to
associate LSPs with each other. For example, in the context of
GMPLS-controlled LSP(s), the object is used to associate recovery
LSPs with the LSP they are protecting. The Extended ASSOCIATION
object is introduced in [RFC6780] to expand on the possible usage of
the ASSOCIATION object and generalize the definition of the Extended
Association ID field.
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This document proposes the use of the Extended ASSOCIATION object to
carry the Summary FRR information and associate the protected LSP(s)
with the bypass tunnel that protects them. Two new Association Types
for the Extended ASSOCIATION object, and new Extended Association IDs
are proposed in this draft to describe the Bypass Summary FRR Ready
(B-SFRR-Ready) and the Bypass Summary FRR Active (B-SFRR-Active)
associations.
The PLR creates and manages the Summary FRR LSP groups
(Bypass_Group_Identifiers) and shares them with the MP via signaling.
Protected LSPs sharing the same egress link and bypass assignment are
grouped together and are assigned the same group. The MP maintains
the PLR group assignments learned via signaling, and acknowledges the
group assignments via signaling. Once the PLR receives the
acknowledgment, FRR signaling can proceed as group based.
The PLR node that supports Summary FRR procedures adds the Extended
ASSOCIATION object with Type B-SFRR-Ready and respective Extended
Association ID in the RSVP Path message of the protected LSP to
inform the MP of the PLR's assigned bypass tunnel, Summary FRR
Bypass_Group_Identifier, and the MESSAGE_ID that the PLR will use to
refresh the protected LSP PATH state after FRR occurs.
The MP node that supports Summary FRR procedures adds the B-SFRR-
Ready Extended ASSOCIATION object and respective Extended Association
ID in the RSVP Resv message of the protected LSP to acknowledge the
PLR's bypass tunnel assignment, and provide the MESSAGE_ID object
that the MP node will use to refresh the protected LSP RESV state
after FRR occurs.
This document also defines a new Association Type for the Extended
ASSOCIATION object and new Extended Association ID to describe the B-
SFRR-Active association. The B-SFRR-Active Extended ASSOCIATION
object and Extended Association ID are sent by PLR after activating
FRR procedures on the PLR. The B-SFRR-Active Extended ASSOCIATION
object and Extended Association ID are sent within the RSVP Path
message of the bypass LSP to inform the MP node that one or more
groups of protected LSPs protected by the bypass tunnel are now being
rerouted over the bypass tunnel.
3.1. B-SFRR-Ready Extended ASSOCIATION Object
The Extended ASSOCIATION object is populated using the rules defined
below to associate a protected LSP with the bypass LSP that is
protecting it when Summary FRR procedures are enabled.
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The Association Type, Association ID, and Association Source MUST be
set as defined in [RFC4872] for the ASSOCIATION Object. More
specifically:
Association Source:
The Association Source is set to an address of the PLR node.
Association Type:
A new Association Type is defined for B-SFRR-Ready as follows:
Value Type
------- ------
(TBD-1) Bypass Summary FRR Ready Association (B-SFRR-Ready)
Extended ASSOCIATION ID for B-SFRR-Ready:
The B-SFRR-Ready Extended ASSOCIATION ID is
populated by the PLR for the Bypass Summary FRR Ready association.
The rules to populate the Extended ASSOCIATION ID in this case are
described below.
3.1.1. IPv4 B-SFRR-Ready IPv4 Extended ASSOCIATION ID
The IPv4 Extended ASSOCIATION ID for the B-SFRR-Ready association
type has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Tunnel_ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Source_IPv4_Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Destination_IPv4_Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Group_Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MESSAGE_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: The IPv4 Extended ASSOCIATION ID for B-SFRR-Ready
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Bypass_Tunnel_ID: 16 bits
The bypass tunnel identifier.
Reserved: 16 bits
Reserved for future use.
Bypass_Source_IPv4_Address: 32 bits
The bypass tunnel source IPV4 address.
Bypass_Destination_IPv4_Address: 32 bits
The bypass tunnel destination IPV4 address.
Bypass_Group_Identifier: 32 bits
The bypass tunnel group identifier.
MESSAGE_ID
A MESSAGE_ID object as defined by [RFC2961].
3.1.2. IPv6 B-SFRR-Ready IPv6 Extended ASSOCIATION ID
The IPv6 Extended ASSOCIATION ID field for the B-SFRR-Ready
association type has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Tunnel_ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Bypass_Source_IPv6_Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Bypass_Destination_IPv6_Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Group_Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MESSAGE_ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: The IPv6 Extended ASSOCIATION ID for B-SFRR-Ready
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Bypass_Tunnel_ID: 16 bits
The bypass tunnel identifier.
Reserved: 16 bits
Reserved for future use.
Bypass_Source_IPv6_Address: 128 bits
The bypass tunnel source IPV6 address.
Bypass_Destination_IPv6_Address: 128 bits
The bypass tunnel destination IPV6 address.
Bypass_Group_Identifier: 32 bits
The bypass tunnel group identifier.
MESSAGE_ID
A MESSAGE_ID object as defined by [RFC2961].
The PLR assigns a bypass tunnel and Bypass_Group_Identifier for each
protected LSP. The same Bypass_Group_Identifier is used for the set
of protected LSPs that share the same bypass tunnel and traverse the
same egress link and are not already rerouted. The PLR also
generates a MESSAGE_ID object (flags SHOULD be clear, Epoch and
Message_Identifier MUST be set according to [RFC2961]).
The PLR MUST generate a new Message_Identifier each time the contents
of the B-SFRR-Ready Extended ASSOCIATION ID changes; for example,
when PLR node changes the bypass tunnel assignment.
The PLR node notifies the MP node of the bypass tunnel assignment via
adding a B-SFRR-Ready Extended ASSOCIATION object and Association ID
in the RSVP Path message for the protected LSP using procedures
described in Section 3.4.
The MP node acknowledges the PLR node assignment by signaling the B-
SFRR-Ready Extended ASSOCIATION object and Association ID within the
RSVP Resv message of the protected LSP. With exception of the
MESSAGE_ID objects, all other fields of the received in the B-SFRR-
Ready Extended ASSOCIATION ID in the RSVP Path message are copied
into the B-SFRR-Ready Extended ASSOCIATION ID to be added in the Resv
message. The MESSAGE_ID object is set according to [RFC2961] with
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the Flags being clear. A new Message_Identifier MUST be used to
acknowledge an updated PLR assignment.
The PLR considers the protected LSP as Summary FRR capable only if
all the fields in the B-SFRR-Ready Extended ASSOCIATION ID that are
sent in the RSVP Path message and the ones received in the RSVP Resv
message (with exception of the MESSAGE_ID) match. If it does not
match, or if B-SFRR-Ready Extended ASSOCIATION object is absent in a
subsequent refresh, the PLR node MUST consider the protected LSP as
not Summary FRR capable.
3.2. B-SFRR-Active Extended ASSOCIATION Object
The Extended ASSOCIATION object for B-SFRR-Active association type is
populated by a PLR node to indicate to the MP node (bypass tunnel
destination) that one or more groups of protected LSPs that are being
protected by the specified bypass tunnel are being rerouted over the
bypass tunnel.
The B-SFRR-Active Extended ASSOCIATION object is carried in the RSVP
Path message of a bypass LSP and signaled downstream towards the MP
(bypass LSP destination).
The Association Type, Association ID, and Association Source MUST be
set as defined in [RFC4872] for the ASSOCIATION Object. More
specifically:
Association Source:
The Association Source is set to an address of the PLR node.
Association Type:
A new Association Type is defined for B-SFRR-Active as follows:
Value Type
------- ------
(TBD-2) Bypass Summary FRR Active Association (B-SFRR-Active)
Extended ASSOCIATION ID for B-SFRR-Active:
The B-SFRR-Active Extended ASSOCIATION ID is
populated by the PLR for the Bypass Summary FRR Active association.
The rules to populate the Extended ASSOCIATION ID in this case are
described below.
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3.2.1. B-SFRR-Active Extended ASSOCIATION ID
The Extended ASSOCIATION ID for the B-SFRR-Active association type
has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Num-BGIDs | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Group_Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bypass_Group_Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RSVP_HOP_Object |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TIME_VALUES |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: The Extended ASSOCIATION ID for B-SFRR-Active
Num-BGIDs: 16 bits
Number of Bypass_Group_Identifier fields.
Reserved: 16 bits
Reserved for future use.
Bypass_Group_Identifier: 32 bits
The Bypass_Group_Identifier that is previously signaled by the
PLR using the Extended Association object. One or
more Bypass_Group_Identifiers may be included.
RSVP_HOP_Object: Class 3, as defined by [RFC2205]
Replacement RSVP HOP object to be applied to all LSPs associated
with each of the following Bypass_Group_Identifiers. This corresponds
to C-Type = 1 for IPv4 RSVP HOP, or C-Type = 2 for IPv6 RSVP HOP
depending on the IP address family carried within the object.
TIME_VALUES object: Class 5, as defined by [RFC2205]
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Replacement TIME_VALUES object to be applied to all LSPs associated
with each of the following Bypass_Group_Identifiers after receiving
the B-SFRR-Active Extended ASSOCIATION Object.
3.3. Signaling Procedures Prior to Failure
Before Summary FRR procedures can be used, a handshake MUST be
completed between the PLR and MP. This handshake is performed using
Extended ASSOCIATION object that carries the B-SFRR-Ready Extended
Association ID in both the RSVP Path and Resv messages of the
protected LSP.
3.3.1. PLR Signaling Procedure
The B-SFRR-Ready Extended ASSOCIATION object is added by each PLR in
the RSVP Path message of the protected LSP to record the bypass
tunnel assignment. This object is updated every time the PLR updates
the bypass tunnel assignment and that triggers an RSVP Path change
message.
Upon receiving an RSVP Resv message with B-SFRR-Ready Extended
ASSOCIATION object, the PLR node checks if the expected subobjects
from the B-SFRR-Ready ASSOCIATION ID are present. If present, the
PLR determines if the MP has acknowledged the current PLR assignment.
To be a valid acknowledgement, the received B-SFRR-Ready ASSOCIATION
ID contents within the RSVP Resv message of the protected LSP MUST
match the latest B-SFRR-Ready Extended ASSOCIATION object and
Association ID contents that the PLR node had sent within the RSVP
Path message (with exception of the MESSAGE_ID).
Note, when forwarding an RSVP Resv message upstream, the PLR node
SHOULD remove any/all B-SFRR-Ready Extended ASSOCIATION objects whose
Association Source matches the PLR node address.
3.3.2. MP Signaling Procedure
Upon receiving an RSVP Path message with a B-SFRR-Ready Extended
ASSOCIATION object, the MP node processes all (there may be multiple
PLRs for a single MP) B-SFRR-Ready Extended ASSOCIATION objects that
have the MP node address as Bypass Destination address in the
Association ID.
The MP node first ensures the existence of the bypass tunnel and that
the Bypass_Group_Identifier is not already FRR active. That is, an
LSP cannot join a group that is already FRR rerouted.
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The MP node builds a mirrored Summary FRR Group database per PLR,
which is determined using the Bypass_Source_Address field. The
MESSAGE_ID is extracted and recorded for the protected LSP PATH
state. The MP node signals a B-SFRR-Ready Extended Association
object and Association ID in the RSVP Resv message of the protected
LSP. With exception of the MESSAGE_ID objects, all other fields of
the received B-SFRR-Ready Extended ASSOCIATION object in the RSVP
Path message are copied into the B-SFRR-Ready Extended ASSOCIATION
object to be added in the Resv message. The MESSAGE_ID object is set
according to [RFC2961] with the Flags being clear.
Note, an MP may receive more than one RSVP Path message with the B-
SFRR-Ready Extended ASSOCIATION object from different upstream PLR
node(s). In this case, the MP node is expected to save all the
received MESSAGE_IDs from the different upstream PLR node(s). After
a failure, the MP node determines and activates the associated
Summary Refresh ID to use once it receives and processes the RSVP
Path message containing B-SFRR-Active Extended ASSOCIATION object
that is signaled over the bypass LSP from the PLR, as described
Section 3.4
When forwarding an RSVP Path message downstream, the MP SHOULD remove
any/all B-SFRR-Ready Extended ASSOCIATION object(s) whose Association
ID contains Bypass_Destination_Address matching the MP node address.
3.4. Signaling Procedures Post Failure
Upon detection of the fault (egress link or node failure) the PLR
first performs the object modification procedures described by
Section 6.4.3 of [RFC4090] for all affected protected LSPs. For
Summary FRR LSPs assigned to the same bypass tunnel a common RSVP_HOP
and SENDER_TEMPLATE MUST be used.
The PLR MUST signal non-Summary FRR enabled LSPs over the bypass
tunnel before signaling the Summary FRR enabled LSPs. This is needed
to allow for the case when the PLR node has recently changed a bypass
assignment and the MP has not processed the change yet.
The B-SFRR-Active Extended ASSOCIATION object is sent within the RSVP
Path message of the bypass LSP to reroute RSVP state of Summary FRR
enabled LSPs.
3.4.1. PLR Signaling Procedure
After a failure event, when using the Summary FRR path signaling
procedures, an individual RSVP Path message for each Summary FRR LSP
is not signaled. Instead, to reroute Summary FRR LSPs via the bypass
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tunnel, the PLR adds the B-SFRR-Active Extended Association object in
the RSVP Path message of the RSVP session of the bypass tunnel.
The RSVP_HOP_Object field in the B-SFRR-Active Extended ASSOCIATION
ID is set to the common RSVP_HOP that was used by the PLR in
Section 3.4 of this document.
The previously received MESSAGE_ID from the MP is activated. As a
result, the MP may refresh the protected rerouted RESV state using
Summary Refresh procedures.
For each affected Summary FRR group, its Bypass_Group_Identifier is
added to B-SFRR-Active Extended ASSOCIATION ID.
3.4.2. MP Signaling Procedure
Upon receiving an RSVP Path message with a B-SFRR-Active Extended
Association object, the MP performs normal merge point processing for
each protected LSP associated with each Bypass_Group_Identifier, as
if it received individual RSVP Path messages for the LSP.
For each Summary FRR LSP being merged, the MP first modifies the Path
state as follows:
1. The RSVP_HOP object is copied from the B-SFRR-Active Extended
ASSOCIATION ID.
2. The TIME_VALUES object is copied from the TIMES_VALUE field in
the B-SFRR-Active Extended ASSOCIATION ID. The TIME_VALUES
object contains the refresh time of the PLR to generate refreshes
and that would have exchanged in a Path message sent to the MP
after the failure when no SFRR procedures are in effect.
3. The SENDER_TEMPLATE object SrcAddress field is copied from the
bypass tunnel SENDER_TEMPLATE object. For the case where PLR is
also the head-end, and SENDER_TEMPLATE SrcAddress of the
protected LSP and bypass tunnel are the same, the MP MUST use the
modified HOP Address field instead.
4. The ERO object is modified as per Section 6.4.4. of [RFC4090].
Once the above modifications are completed, the MP then performs
the merge processing as per [RFC4090].
5. The previously received MESSAGE_ID from the PLR is activated,
meaning that the PLR may now refresh the protected rerouted PATH
state using Summary Refresh procedures.
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A failure during merge processing of any individual rerouted LSP MUST
result in an RSVP Path Error message.
An individual RSVP Resv message for each successfully merged Summary
FRR LSP is not signaled. The MP node SHOULD immediately use Summary
Refresh procedures to refresh the protected LSP RESV state.
3.5. Refreshing Summary FRR Active LSPs
Refreshing of Summary FRR active LSPs is performed using Summary
Refresh as defined by [RFC2961].
4. Compatibility
The (Extended) ASSOCIATION object is defined in [RFC4872] with a
class number in the form 11bbbbbb, which ensures compatibility with
non-supporting node(s). Such nodes will ignore the object and
forward it without modification.
5. Security Considerations
This document updates an existing RSVP object. Thus, in the event of
the interception of a signaling message, a slightly more information
could be deduced about the state of the network than was previously
the case. Existing mechanisms for maintaining the integrity and
authenticity of RSVP protocol messages [RFC2747] can be applied.
Other considerations mentioned in [RFC4090] and [RFC5920] also apply.
6. IANA Considerations
IANA maintains the "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Parameters" registry (see
http://www.iana.org/assignments/gmpls-sig-parameters [1]). The
"Association Type" subregistry is included in this registry.
This registry has been updated by new Association Type for Extended
ASSOCIATION Object defined in this document as follows:
Value Name Reference
----- ---- ---------
TBD-1 B-SFRR-Ready Association Section 3.1
TBD-2 B-SFRR-Active Association Section 3.2
IANA also maintains and assigns the values for the RSVP-TE protocol
parameters "Resource Reservation Protocol (RSVP) Parameters" (see
http://www.iana.org/assignments/rsvp-parameters).
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7. Acknowledgments
The authors would like to thank Loa Andersson, Lou Berger, Eric
Osborne, Gregory Mirsky, and Mach Chen for reviewing and providing
valuable comments to this document.
8. Contributors
Nicholas Tan
Arista Networks
Email: ntan@arista.com
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
September 1997, <https://www.rfc-editor.org/info/rfc2205>.
[RFC2747] Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
Authentication", RFC 2747, DOI 10.17487/RFC2747, January
2000, <https://www.rfc-editor.org/info/rfc2747>.
[RFC2961] Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F.,
and S. Molendini, "RSVP Refresh Overhead Reduction
Extensions", RFC 2961, DOI 10.17487/RFC2961, April 2001,
<https://www.rfc-editor.org/info/rfc2961>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC4090] Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast
Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
DOI 10.17487/RFC4090, May 2005,
<https://www.rfc-editor.org/info/rfc4090>.
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[RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
Ed., "RSVP-TE Extensions in Support of End-to-End
Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
<https://www.rfc-editor.org/info/rfc4872>.
[RFC6780] Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP
ASSOCIATION Object Extensions", RFC 6780,
DOI 10.17487/RFC6780, October 2012,
<https://www.rfc-editor.org/info/rfc6780>.
9.2. Informative References
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>.
9.3. URIs
[1] http://www.iana.org/assignments/gmpls-sig-parameters
Authors' Addresses
Mike Taillon
Cisco Systems, Inc.
Email: mtaillon@cisco.com
Tarek Saad (editor)
Juniper Networks
Email: tsaad@juniper.net
Rakesh Gandhi
Cisco Systems, Inc.
Email: rgandhi@cisco.com
Abhishek Deshmukh
Juniper Networks
Email: adeshmukh@juniper.net
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Markus Jork
128 Technology
Email: mjork@128technology.com
Vishnu Pavan Beeram
Juniper Networks
Email: vbeeram@juniper.net
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