draft-ietf-teas-rsvp-te-scaling-rec-09.txt   rfc8370.txt 
TEAS Working Group V. Beeram, Ed. Internet Engineering Task Force (IETF) V. Beeram, Ed.
Internet-Draft Juniper Networks Request for Comments: 8370 Juniper Networks
Intended status: Standards Track I. Minei Category: Standards Track I. Minei
Expires: August 18, 2018 R. Shakir ISSN: 2070-1721 R. Shakir
Google, Inc Google, Inc
D. Pacella D. Pacella
Verizon Verizon
T. Saad T. Saad
Cisco Systems Cisco Systems
February 14, 2018 May 2018
Techniques to Improve the Scalability of RSVP Traffic Engineering Techniques to Improve the Scalability of RSVP-TE Deployments
Deployments
draft-ietf-teas-rsvp-te-scaling-rec-09
Abstract Abstract
At the time of writing, networks which utilize RSVP Traffic Networks that utilize RSVP-TE LSPs are encountering implementations
Engineering (RSVP-TE) Label Switched Paths (LSPs) are encountering that have a limited ability to support the growth in the number of
limitations in the ability of implementations to support the growth LSPs deployed.
in the number of LSPs deployed.
This document defines two techniques, "Refresh-Interval Independent This document defines two techniques, Refresh-Interval Independent
RSVP (RI-RSVP)" and "Per-Peer Flow-Control", that reduce the number RSVP (RI-RSVP) and Per-Peer Flow Control, that reduce the number of
of processing cycles required to maintain RSVP-TE LSP state in Label processing cycles required to maintain RSVP-TE LSP state in Label
Switching Routers (LSRs) and hence allow implementations to support Switching Routers (LSRs) and hence allow implementations to support
larger scale deployments. larger scale deployments.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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 http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on August 18, 2018. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8370.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirement for RFC2961 Support . . . . . . . . . . . . . . . 3 2. Required Support for RFC 2961 . . . . . . . . . . . . . . . . 4
2.1. Required Functionality from RFC2961 to be Implemented . . 4 2.1. Required Functionality from RFC 2961 . . . . . . . . . . 4
2.2. Making Acknowledgements Mandatory . . . . . . . . . . . . 4 2.2. Making Acknowledgements Mandatory . . . . . . . . . . . . 4
3. Refresh-Interval Independent RSVP (RI-RSVP) . . . . . . . . . 4 3. Refresh-Interval Independent RSVP (RI-RSVP) . . . . . . . . . 5
3.1. Capability Advertisement . . . . . . . . . . . . . . . . 5 3.1. Capability Advertisement . . . . . . . . . . . . . . . . 6
3.2. Compatibility . . . . . . . . . . . . . . . . . . . . . . 6 3.2. Compatibility . . . . . . . . . . . . . . . . . . . . . . 6
4. Per-Peer RSVP Flow-Control . . . . . . . . . . . . . . . . . 6 4. Per-Peer Flow Control . . . . . . . . . . . . . . . . . . . . 6
4.1. Capability Advertisement . . . . . . . . . . . . . . . . 7 4.1. Capability Advertisement . . . . . . . . . . . . . . . . 7
4.2. Compatibility . . . . . . . . . . . . . . . . . . . . . . 7 4.2. Compatibility . . . . . . . . . . . . . . . . . . . . . . 7
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Capability Object Values . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7.1. Capability Object Values . . . . . . . . . . . . . . . . 8 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7.1. Normative References . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.2. Informative References . . . . . . . . . . . . . . . . . 9
9.1. Normative References . . . . . . . . . . . . . . . . . . 8 Appendix A. Recommended Defaults . . . . . . . . . . . . . . . . 10
9.2. Informative References . . . . . . . . . . . . . . . . . 9 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 10
Appendix A. Recommended Defaults . . . . . . . . . . . . . . . . 9 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
At the time of writing, networks which utilize RSVP Traffic Networks that utilize RSVP-TE [RFC3209] LSPs are encountering
Engineering (RSVP-TE) [RFC3209] Label Switched Paths (LSPs) are implementations that have a limited ability to support the growth in
encountering limitations in the ability of implementations to support the number of LSPs deployed.
the growth in the number of LSPs deployed.
The set of RSVP Refresh Overhead Reduction procedures [RFC2961] The set of RSVP Refresh Overhead Reduction procedures [RFC2961]
serves as a powerful toolkit for RSVP-TE implementations to help serves as a powerful toolkit for RSVP-TE implementations to help
cover a majority of the concerns about soft-state scaling. However, cover a majority of the concerns about soft-state scaling. However,
even with these tools in the toolkit, analysis of existing even with these tools in the toolkit, analysis of existing
implementations [RFC5439] indicates that the processing required implementations [RFC5439] indicates that the processing required
beyond a certain scale may still cause significant disruption to a beyond a certain scale may still cause significant disruption to a
Label Switching Router (LSR). Label Switching Router (LSR).
This document builds on the scaling work and analysis that has been This document builds on existing scaling work and analysis and
done so far and defines protocol extensions to help RSVP-TE defines protocol extensions to help RSVP-TE deployments push the
deployments push the envelope further on scaling by increasing the envelope further on scaling by increasing the threshold above which
threshold above which an LSR struggles to achieve sufficient an LSR struggles to achieve sufficient processing to maintain LSP
processing to maintain LSP state. state.
This document defines two techniques, "Refresh-Interval Independent This document defines two techniques, Refresh-Interval Independent
RSVP (RI-RSVP)" and "Per-Peer Flow-Control", that cut down the number RSVP (RI-RSVP) and Per-Peer Flow Control, that cut down the number of
of processing cycles required to maintain LSP state. "RI-RSVP" helps processing cycles required to maintain LSP state. RI-RSVP helps
completely eliminate RSVP's reliance on refreshes and refresh- completely eliminate RSVP's reliance on refreshes and refresh
timeouts while "Per-Peer Flow-Control" enables a busy RSVP speaker to timeouts, while Per-Peer Flow Control enables a busy RSVP speaker to
apply back pressure to its peer(s). This document defines a unique apply back pressure to its peer(s). This document defines a unique
RSVP Capability [RFC5063] for each technique (Support for CAPABILITY RSVP Capability [RFC5063] for each technique (support for the
object is a prerequisite for implementing these techniques). Note CAPABILITY object is a prerequisite for implementing these
that the "Per-Peer Flow-Control" technique requires the "RI-RSVP" techniques). Note that the Per-Peer Flow-Control technique requires
technique as a prerequisite. In order to reap maximum scaling the RI-RSVP technique as a prerequisite. In order to reap maximum
benefits, it is strongly recommended that implementations support scaling benefits, it is strongly recommended that implementations
both the techniques and have them enabled by default. Both the support both techniques and have them enabled by default. Both
techniques are fully backward compatible and can be deployed techniques are fully backward compatible and can be deployed
incrementally. incrementally.
2. Requirement for RFC2961 Support The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The techniques defined in Section 3 and Section 4 are based on 2. Required Support for RFC 2961
proposals made in [RFC2961]. Implementations of these techniques
will need to support the RSVP messages and procedures defined in
[RFC2961] with some minor modifications and alterations to
recommended time intervals and iteration counts (see Appendix A for
the set of recommended defaults).
2.1. Required Functionality from RFC2961 to be Implemented The techniques defined in Sections 3 and 4 are based on proposals
made in [RFC2961]. Implementations of these techniques need to
support the RSVP messages and procedures defined in [RFC2961] with
some minor modifications and alterations to recommended time
intervals and iteration counts (see Appendix A for the set of
recommended defaults).
An implementation that supports the techniques discussed in Section 3 2.1. Required Functionality from RFC 2961
and Section 4 must support the functionality described in [RFC2961]
as follows: An implementation that supports the techniques discussed in Sections
3 and 4 must support the functionality described in [RFC2961] as
follows:
o It MUST indicate support for RSVP Refresh Overhead Reduction o It MUST indicate support for RSVP Refresh Overhead Reduction
extensions (as specified in Section 2 of [RFC2961]). extensions (as specified in Section 2 of [RFC2961]).
o It MUST support receipt of any RSVP Refresh Overhead Reduction o It MUST support receipt of any RSVP Refresh Overhead Reduction
message as defined in [RFC2961]. message as defined in [RFC2961].
o It MUST initiate all RSVP Refresh Overhead Reduction mechanisms as o It MUST initiate all RSVP Refresh Overhead Reduction mechanisms as
defined in [RFC2961] (including the SRefresh message) with the defined in [RFC2961] (including the SRefresh message) with the
default behavior being to initiate the mechanisms but offering a default behavior being to initiate the mechanisms; however, a
configuration override. configuration override should be offered.
o It MUST support reliable delivery of Path/Resv and the o It MUST support reliable delivery of Path/Resv and the
corresponding Tear/Err messages (as specified in Section 4 of corresponding Tear/Err messages (as specified in Section 4 of
[RFC2961]). [RFC2961]).
o It MUST support retransmission of all unacknowledged RSVP-TE o It MUST support retransmission of all unacknowledged RSVP-TE
messages using exponential-backoff (as specified in Section 6 of messages using exponential backoff (as specified in Section 6 of
[RFC2961]). [RFC2961]).
2.2. Making Acknowledgements Mandatory 2.2. Making Acknowledgements Mandatory
The reliable message delivery mechanism specified in [RFC2961] states The reliable message delivery mechanism specified in [RFC2961] states
that "Nodes receiving a non-out of order message containing a that "Nodes receiving a non-out of order [sic] message containing a
MESSAGE_ID object with the ACK_Desired flag set, SHOULD respond with MESSAGE_ID object with the ACK_Desired flag set, SHOULD respond with
a MESSAGE_ID_ACK object." a MESSAGE_ID_ACK object."
In an implementation that supports the techniques discussed in In an implementation that supports the techniques discussed in
Section 3 and Section 4, nodes receiving a non-out of order message Sections 3 and 4, nodes receiving a non-out-of-order message
containing a MESSAGE_ID object with the ACK-Desired flag set, MUST containing a MESSAGE_ID object with the ACK_Desired flag set MUST
respond with a MESSAGE_ID_ACK object. This MESSAGE_ID_ACK object can respond with a MESSAGE_ID_ACK object. This MESSAGE_ID_ACK object can
be packed along with other MESSAGE_ID_ACK or MESSAGE_ID_NACK objects be packed with other MESSAGE_ID_ACK or MESSAGE_ID_NACK objects and
and sent in an Ack message (or piggy-backed in any other RSVP sent in an Ack message (or piggybacked in any other RSVP message).
message). This improvement to the predictability of the system in
terms of reliable message delivery is key for being able to take any This improvement to the predictability of the system in terms of
action based on a non-receipt of an ACK. reliable message delivery is key for being able to take any action
based on a non-receipt of an ACK.
3. Refresh-Interval Independent RSVP (RI-RSVP) 3. Refresh-Interval Independent RSVP (RI-RSVP)
The RSVP protocol relies on periodic refreshes for state The RSVP protocol relies on periodic refreshes for state
synchronization between RSVP neighbors and for recovery from lost synchronization between RSVP neighbors and recovery from lost RSVP
RSVP messages. It relies on refresh timeout for stale state cleanup. messages. It relies on a refresh timeout for stale-state cleanup.
The primary motivation behind introducing the notion of "Refresh The primary motivation behind introducing the notion of Refresh-
Interval Independent RSVP" (RI-RSVP) is to completely eliminate Interval Independent RSVP (RI-RSVP) is to completely eliminate RSVP's
RSVP's reliance on refreshes and refresh timeouts. This is done by reliance on refreshes and refresh timeouts. This is done by simply
simply increasing the refresh interval to a fairly large value. increasing the refresh interval to a fairly large value. [RFC2961]
[RFC2961] and [RFC5439] do talk about increasing the value of the and [RFC5439] talk about increasing the value of the refresh interval
refresh interval to provide linear improvement of transmission to provide linear improvement of transmission overhead, but they also
overhead, but also point out the degree of functionality that is lost point out the degree of functionality that is lost by doing so. This
by doing so. This section revisits this notion, but also sets out section revisits this notion, but also sets out additional
additional requirements to make sure that there is no loss of requirements to make sure that there is no loss of functionality
functionality incurred by increasing the value of the refresh incurred by increasing the value of the refresh interval.
interval.
An implementation that supports RI-RSVP: An implementation that supports RI-RSVP:
o MUST support all the requirements specified in Section 2. o MUST support all of the requirements specified in Section 2.
o MUST make the default value of the configurable refresh interval o MUST make the default value of the configurable refresh interval
(R) be a large value (10s of minutes). A default value of 20 (R) be a large value (tens of minutes). A default value of 20
minutes is RECOMMENDED by this document. minutes is RECOMMENDED by this document.
o MUST use a separate shorter refresh interval for refreshing state o MUST use a separate shorter refresh interval for refreshing state
associated with unacknowledged Path/Resv messages (uR). A default associated with unacknowledged Path/Resv (uR) messages. A default
value of 30 seconds is RECOMMENDED by this document. value of 30 seconds is RECOMMENDED by this document.
o MUST implement coupling the state of individual LSPs with the o MUST implement coupling the state of individual LSPs with the
state of the corresponding RSVP-TE signaling adjacency. When an state of the corresponding RSVP-TE signaling adjacency. When an
RSVP-TE speaker detects RSVP-TE signaling adjacency failure, the RSVP-TE speaker detects RSVP-TE signaling adjacency failure, the
speaker MUST act as if all the Path and Resv states learnt via the speaker MUST act as if all the Path and Resv states learned via
failed signaling adjacency have timed out. the failed signaling adjacency have timed out.
o MUST make use of Node-ID based Hello Session ([RFC3209], o MUST make use of the Hello session based on the Node-ID ([RFC3209]
[RFC4558]) for detection of RSVP-TE signaling adjacency failures; [RFC4558]) for detection of RSVP-TE signaling adjacency failures.
A default value of 9 seconds is RECOMMENDED by this document for A default value of 9 seconds is RECOMMENDED by this document for
the configurable node hello interval (as opposed to the 5ms the configurable node hello interval (as opposed to the default
default value proposed in Section 5.3 of [RFC3209]). value of 5 milliseconds proposed in Section 5.3 of [RFC3209]).
o MUST indicate support for RI-RSVP via the CAPABILITY object o MUST indicate support for RI-RSVP via the CAPABILITY object
[RFC5063] in Hello messages. [RFC5063] in Hello messages.
3.1. Capability Advertisement 3.1. Capability Advertisement
An implementation supporting the RI-RSVP technique MUST set a new An implementation supporting the RI-RSVP technique MUST set a new
flag "RI-RSVP Capable" in the CAPABILITY object signaled in Hello flag, RI-RSVP Capable, in the CAPABILITY object signaled in Hello
messages. messages. The following bit indicates that the sender supports
RI-RSVP:
Bit Number TBA1 (TBA2) - RI-RSVP Capable (I-bit):
Indicates that the sender supports RI-RSVP. Bit Number 28 (0x0008) - RI-RSVP Capable (I-bit)
Any node that sets the new I-bit in its CAPABILITY object MUST also Any node that sets the new I-bit in its CAPABILITY object MUST also
set the Refresh-Reduction-Capable bit in the common header of all set the Refresh-Reduction-Capable bit [RFC2961] in the common header
RSVP-TE messages. If a peer sets the I-bit in the CAPABILITY object of all RSVP-TE messages. If a peer sets the I-bit in the CAPABILITY
but does not set the Refresh-Reduction-Capable bit, then the RI-RSVP object but does not set the Refresh-Reduction-Capable bit, then the
functionality MUST NOT be activated for that peer. RI-RSVP functionality MUST NOT be activated for that peer.
3.2. Compatibility 3.2. Compatibility
The RI-RSVP functionality MUST NOT be activated with a peer that does The RI-RSVP functionality MUST NOT be activated with a peer that does
not indicate support for this functionality. Inactivation of the RI- not indicate support for this functionality. Inactivation of the
RSVP functionality MUST result in the use of the traditional smaller RI-RSVP functionality MUST result in the use of the traditional
refresh interval [RFC2205]. smaller refresh interval [RFC2205].
4. Per-Peer RSVP Flow-Control 4. Per-Peer Flow Control
The functionality discussed in this section provides an RSVP speaker The functionality discussed in this section provides an RSVP speaker
with the ability to apply back pressure to its peer(s) to reduce/ with the ability to apply back pressure to its peer(s) to reduce/
eliminate a significant portion of the RSVP-TE control message load. eliminate a significant portion of the RSVP-TE control message load.
An implementation that supports "Per-Peer RSVP Flow-Control": An implementation that supports Per-Peer Flow Control:
o MUST support all the requirements specified in Section 2. o MUST support all of the requirements specified in Section 2.
o MUST support "RI-RSVP" (Section 3). o MUST support RI-RSVP (Section 3).
o MUST treat lack of ACKs from a peer as an indication of peer's o MUST treat lack of ACKs from a peer as an indication of a peer's
RSVP-TE control plane congestion. If congestion is detected, the RSVP-TE control-plane congestion. If congestion is detected, the
local system MUST throttle RSVP-TE messages to the affected peer. local system MUST throttle RSVP-TE messages to the affected peer.
This MUST be done on a per-peer basis. (Per-peer throttling MAY This MUST be done on a per-peer basis. (Per-peer throttling MAY
be implemented by a traffic shaping mechanism that proportionally be implemented by a traffic-shaping mechanism that proportionally
reduces the RSVP signaling packet rate as the number of reduces the RSVP-signaling packet rate as the number of
outstanding Acks increases. And when the number of outstanding outstanding ACKs increases. When the number of outstanding ACKs
Acks decreases, the send rate would be adjusted up again.) decreases, the send rate would be adjusted up again.)
o SHOULD use a Retry Limit (Rl) value of 7 (Section 6.2 of o SHOULD use a Retry Limit (Rl) value of 7 (Section 6.2 of [RFC2961]
[RFC2961], suggests using 3). suggests using 3).
o SHOULD prioritize Hello messages and messages carrying o SHOULD prioritize Hello messages and messages carrying
Acknowledgements over other RSVP messages. Acknowledgements over other RSVP messages.
o SHOULD prioritize Tear/Error over trigger Path/Resv (messages that o SHOULD prioritize Tear/Error over trigger Path/Resv (messages that
bring up new LSP state) sent to a peer when the local system bring up new LSP state) sent to a peer when the local system
detects RSVP-TE control plane congestion in the peer. detects RSVP-TE control-plane congestion in the peer.
o MUST indicate support for this technique via the CAPABILITY object o MUST indicate support for this technique via the CAPABILITY object
[RFC5063] in Hello messages. [RFC5063] in Hello messages.
4.1. Capability Advertisement 4.1. Capability Advertisement
An implementation supporting the "Per-Peer Flow-Control" technique An implementation supporting the Per-Peer Flow-Control technique MUST
MUST set a new flag "Per-Peer Flow-Control Capable" in the CAPABILITY set a new flag, Per-Peer Flow-Control Capable, in the CAPABILITY
object signaled in Hello messages. object signaled in Hello messages. The following bit indicates that
the sender supports Per-Peer Flow Control:
Bit Number TBA3 (TBA4) - Per-Peer Flow-Control Capable (F-bit):
Indicates that the sender supports Per-Peer RSVP Flow-Control. Bit Number 27 (0x0010) - Per-Peer Flow-Control Capable (F-bit)
Any node that sets the new F-bit in its CAPABILITY object MUST also Any node that sets the new F-bit in its CAPABILITY object MUST also
set Refresh-Reduction-Capable bit in common header of all RSVP-TE set the Refresh-Reduction-Capable bit in the common header of all
messages. If a peer sets the F-bit in the CAPABILITY object but does RSVP-TE messages. If a peer sets the F-bit in the CAPABILITY object
not set the Refresh-Reduction-Capable bit, then the Per-Peer Flow- but does not set the Refresh-Reduction-Capable bit, then the Per-Peer
Control functionality MUST NOT be activated for that peer. Flow-Control functionality MUST NOT be activated for that peer.
4.2. Compatibility 4.2. Compatibility
The Per-Peer Flow-Control functionality MUST NOT be activated with a The Per-Peer Flow-Control functionality MUST NOT be activated with a
peer that does not indicate support for this functionality. If a peer that does not indicate support for this functionality. If a
peer hasn't indicated that it is capable of participating in "Per- peer hasn't indicated that it is capable of participating in Per-Peer
Peer Flow-Control", then it SHOULD NOT be assumed that the peer would Flow Control, then it SHOULD NOT be assumed that the peer would
always acknowledge a non-out of order message containing a MESSAGE_ID always acknowledge a non-out-of-order message containing a MESSAGE_ID
object with the ACK-Desired flag set. object with the ACK_Desired flag set.
5. Acknowledgements
The authors would like to thank Yakov Rekhter for initiating this
work and providing valuable inputs. They would like to thank
Raveendra Torvi and Chandra Ramachandran for participating in the
many discussions that led to the techniques discussed in this
document. They would also like to thank Adrian Farrel, Lou Berger
and Elwyn Davies for providing detailed review comments and text
suggestions.
6. Contributors
Markus Jork
Juniper Networks
Email: mjork@juniper.net
Ebben Aries
Juniper Networks
Email: exa@juniper.net
7. IANA Considerations
7.1. Capability Object Values 5. IANA Considerations
IANA maintains all the registries associated with "Resource 5.1. Capability Object Values
Reservation Protocol (RSVP) Paramaters" (see
http://www.iana.org/assignments/rsvp-parameters/rsvp-
parameters.xhtml). "Capability Object Values" Registry (introduced
by [RFC5063]) is one of them.
IANA is requested to assign two new Capability Object Value bit flags IANA maintains the "Capability Object values" subregistry [RFC5063]
as follows: within the "Resource Reservation Protocol (RSVP) Parameters" registry
<http://www.iana.org/assignments/rsvp-parameters>. IANA has assigned
two new Capability Object Value bit flags as follows:
Bit Hex Name Reference Bit Hex Name Reference
Number Value Number Value
------------------------------------------------------------------ ------------------------------------------------------------------
TBA1 TBA2 RI-RSVP Capable (I) Section 3 28 0x0008 RI-RSVP Capable (I) Section 3
TBA3 TBA4 Per-Peer Flow-Control Capable (F) Section 4 27 0x0010 Per-Peer Flow-Control Capable (F) Section 4
8. Security Considerations 6. Security Considerations
This document does not introduce new security issues. The security This document does not introduce new security issues. The security
considerations pertaining to the original RSVP protocol [RFC2205] and considerations pertaining to the original RSVP protocol [RFC2205] and
RSVP-TE [RFC3209] and those that are described in [RFC5920] remain RSVP-TE [RFC3209], and those that are described in [RFC5920], remain
relevant. relevant.
9. References 7. References
9.1. Normative References 7.1. 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, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
Functional Specification", RFC 2205, DOI 10.17487/RFC2205, Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
September 1997, <https://www.rfc-editor.org/info/rfc2205>. September 1997, <https://www.rfc-editor.org/info/rfc2205>.
[RFC2961] Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F., [RFC2961] Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F.,
and S. Molendini, "RSVP Refresh Overhead Reduction and S. Molendini, "RSVP Refresh Overhead Reduction
Extensions", RFC 2961, DOI 10.17487/RFC2961, April 2001, Extensions", RFC 2961, DOI 10.17487/RFC2961, April 2001,
<https://www.rfc-editor.org/info/rfc2961>. <https://www.rfc-editor.org/info/rfc2961>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>. <https://www.rfc-editor.org/info/rfc3209>.
[RFC4558] Ali, Z., Rahman, R., Prairie, D., and D. Papadimitriou, [RFC4558] Ali, Z., Rahman, R., Prairie, D., and D. Papadimitriou,
"Node-ID Based Resource Reservation Protocol (RSVP) Hello: "Node-ID Based Resource Reservation Protocol (RSVP) Hello:
A Clarification Statement", RFC 4558, A Clarification Statement", RFC 4558,
DOI 10.17487/RFC4558, June 2006, <https://www.rfc- DOI 10.17487/RFC4558, June 2006,
editor.org/info/rfc4558>. <https://www.rfc-editor.org/info/rfc4558>.
[RFC5063] Satyanarayana, A., Ed. and R. Rahman, Ed., "Extensions to [RFC5063] Satyanarayana, A., Ed. and R. Rahman, Ed., "Extensions to
GMPLS Resource Reservation Protocol (RSVP) Graceful GMPLS Resource Reservation Protocol (RSVP) Graceful
Restart", RFC 5063, DOI 10.17487/RFC5063, October 2007, Restart", RFC 5063, DOI 10.17487/RFC5063, October 2007,
<https://www.rfc-editor.org/info/rfc5063>. <https://www.rfc-editor.org/info/rfc5063>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References 7.2. Informative References
[RFC5439] Yasukawa, S., Farrel, A., and O. Komolafe, "An Analysis of [RFC5439] Yasukawa, S., Farrel, A., and O. Komolafe, "An Analysis of
Scaling Issues in MPLS-TE Core Networks", RFC 5439, Scaling Issues in MPLS-TE Core Networks", RFC 5439,
DOI 10.17487/RFC5439, February 2009, <https://www.rfc- DOI 10.17487/RFC5439, February 2009,
editor.org/info/rfc5439>. <https://www.rfc-editor.org/info/rfc5439>.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010, Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>. <https://www.rfc-editor.org/info/rfc5920>.
Appendix A. Recommended Defaults Appendix A. Recommended Defaults
(a) Refresh-Interval (R)- 20 minutes (Section 3): a. Refresh Interval (R) - 20 minutes (Section 3):
Given that an implementation supporting RI-RSVP doesn't rely on Given that an implementation supporting RI-RSVP doesn't rely on
refreshes for state sync between peers, the function of RSVP refreshes for state sync between peers, the function of the RSVP
refresh interval is analogous to that of IGP refresh interval (the refresh interval is analogous to that of IGP refresh interval
default of which is typically in the order of 10s of minutes). (the default of which is typically in the order of tens of
Choosing a default of 20 minutes allows the refresh timer to be minutes). Choosing a default of 20 minutes allows the refresh
randomly set to a value in the range [10 minutes (0.5R), 30 timer to be randomly set to a value in the range [10 minutes
minutes (1.5R)]. (0.5R), 30 minutes (1.5R)].
(b) Node Hello-Interval - 9 Seconds (Section 3): b. Node Hello Interval - 9 seconds (Section 3):
[RFC3209] defines the hello timeout as 3.5 times the hello
interval. Choosing 9 seconds for the node hello-interval gives a
hello timeout of 3.5*9 = 31.5 seconds. This puts the hello
timeout value in the vicinity of the IGP hello timeout value.
(c) Retry-Limit (Rl) - 7 (Section 4): [RFC3209] defines the hello timeout as 3.5 times the hello
Choosing 7 as the retry-limit results in an overall rapid interval. Choosing 9 seconds for the node hello interval gives a
retransmit phase of 31.5 seconds. This matches up with the 31.5 hello timeout of 3.5 * 9 = 31.5 seconds. This puts the hello
seconds hello timeout. timeout value in the vicinity of the IGP hello timeout value.
(d) Refresh-Interval for refreshing state associated with c. Retry-Limit (Rl) - 7 (Section 4):
unacknowledged Path/Resv messages (uR) - 30 seconds (Section 3): Choosing 7 as the retry-limit results in an overall rapid
The recommended refresh interval (R) value of 20 minutes (for an retransmit phase of 31.5 seconds. This matches up with the hello
implementation supporting RI-RSVP) can not be used for refreshing timeout of 31.5 seconds.
state associated with unacknowledged Path/Resv messages. This
document recommends the use of the traditional default refresh d. Refresh Interval for refreshing state associated with
interval value of 30 seconds for uR. unacknowledged Path/Resv messages (uR) - 30 seconds (Section 3):
The recommended refresh interval (R) value of 20 minutes (for an
implementation supporting RI-RSVP) cannot be used for refreshing
state associated with unacknowledged Path/Resv messages. This
document recommends the use of the traditional default refresh
interval value of 30 seconds for uR.
Acknowledgements
The authors would like to thank Yakov Rekhter for initiating this
work and providing valuable input. They would like to thank
Raveendra Torvi and Chandra Ramachandran for participating in the
many discussions that led to the techniques discussed in this
document. They would also like to thank Adrian Farrel, Lou Berger,
and Elwyn Davies for providing detailed review comments and text
suggestions.
Contributors
Markus Jork
Juniper Networks
Email: mjork@juniper.net
Ebben Aries
Juniper Networks
Email: exa@juniper.net
Authors' Addresses Authors' Addresses
Vishnu Pavan Beeram (editor) Vishnu Pavan Beeram (editor)
Juniper Networks Juniper Networks
Email: vbeeram@juniper.net Email: vbeeram@juniper.net
Ina Minei Ina Minei
Google, Inc Google, Inc
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