draft-ietf-mpls-3209-patherr-00.txt   draft-ietf-mpls-3209-patherr-01.txt 
Networking Working Group JP. Vasseur, Ed. Networking Working Group JP. Vasseur, Ed.
Internet-Draft George. Swallow Internet-Draft George. Swallow
Intended status: Best Current Cisco Systems, Inc Intended status: Best Current Cisco Systems, Inc
Practice Adrian. Farrel Practice Adrian. Farrel
Expires: November 4, 2007 Old Dog Consulting Expires: August 11, 2008 Old Dog Consulting
May 3, 2007 Ina. Minei
Juniper Networks
February 8, 2008
Node behavior upon originating and receiving Resource ReserVation Node behavior upon originating and receiving Resource ReserVation
Protocol (RSVP) Path Error message Protocol (RSVP) Path Error message
draft-ietf-mpls-3209-patherr-00.txt draft-ietf-mpls-3209-patherr-01.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
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The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
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This Internet-Draft will expire on November 4, 2007. This Internet-Draft will expire on August 11, 2008.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
Abstract Abstract
The aim of this document is to describe a common practice with regard The aim of this document is to describe a common practice with regard
to the behavior of a node sending a Resource ReserVation Protocol to the behavior of a node sending a Resource ReserVation Protocol
(RSVP) Path Error message and to the behavior of a node receiving an (RSVP) Traffic Engineering (TE) Path Error message and to the
RSVP Path Error message for a particular Multi-Protocol Label behavior of a node receiving an RSVP Path Error message for a
Switching - Traffic Engineering (MPLS-TE) Label Switched Path (LSP). preempted Multi-Protocol Label Switching (MPLS) Traffic Engineering
Label Switched Path (TE LSP). This document does not define any new
This document does not define any new protocol extensions. protocol extensions.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Table of Contents Table of Contents
1. Protocol behavior . . . . . . . . . . . . . . . . . . . . . . . 3 1. Protocol behavior . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Behavior at Detecting Nodes . . . . . . . . . . . . . . . . 4 1.1. Behavior at Detecting Nodes . . . . . . . . . . . . . . . . 4
1.2. Behavior at Receiving Nodes . . . . . . . . . . . . . . . . 4 1.2. Behavior at Receiving Nodes . . . . . . . . . . . . . . . . 4
1.3. Data Plane Behavior . . . . . . . . . . . . . . . . . . . . 5 1.3. Data Plane Behavior . . . . . . . . . . . . . . . . . . . . 5
2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 2. RSVP PathErr Messages For a Preempted TE LSP . . . . . . . . . 5
3. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
5. URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Normative References . . . . . . . . . . . . . . . . . . . . . 6
6. Normative References . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . . 8
Intellectual Property and Copyright Statements . . . . . . . . . . 9
1. Protocol behavior 1. Protocol behavior
[RFC2205] defines two RSVP error message types: PathErr and ResvErr [RFC2205] defines two RSVP error message types: PathErr and ResvErr
that are generated when an error occurs. Path Error Messages that are generated when an error occurs. Path Error Messages
(PathErr) are used to report errors and travel upstream toward the (PathErr) are used to report errors and travel upstream toward the
head-end of the flow. Resv Error messages (ResvErr) travel head-end of the flow. Resv Error messages (ResvErr) travel
downstream toward the tail-end of the flow. downstream toward the tail-end of the flow.
This document describes only PathErr message processing. PathErr This document describes only PathErr message processing for the
specific case of a preempted Traffic Engineering Label Switched Path
(TE LSP) where the term preemption is defined in [RFC3209]. PathErr
messages are routed hop-by-hop using the path state established when messages are routed hop-by-hop using the path state established when
a Path message is routed through the network from the head-end to its a Path message is routed through the network from the head-end to its
tail-end. tail-end.
As stated in [RFC2205], PathErr messages do not modify the state of As stated in [RFC2205], PathErr messages do not modify the state of
any node through which they pass; they are only reported to the head- any node through which they pass; they are only reported to the head-
end of the TE LSP (Traffic Engineering Label Switched Path). end of the TE LSP (Traffic Engineering Label Switched Path).
The format of the PathErr message as defined in [RFC2205] is as The format of the PathErr message as defined in [RFC2205] is as
follows: follows:
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[ <ADSPEC> ] [ <ADSPEC> ]
The ERROR_SPEC object includes the IP address of the node that The ERROR_SPEC object includes the IP address of the node that
detected the error (Error Node Address), and specifies the error detected the error (Error Node Address), and specifies the error
through two fields. The Error Code field encodes the category of the through two fields. The Error Code field encodes the category of the
error, for example, Policy Control Failure or Unknown object class. error, for example, Policy Control Failure or Unknown object class.
The Error Value field qualifies the error code to indicate the error The Error Value field qualifies the error code to indicate the error
with more precision. [RFC3209] extends RSVP as defined in [RFC2205] with more precision. [RFC3209] extends RSVP as defined in [RFC2205]
for the management of Multi-Protocol Label Switching (MPLS) Traffic for the management of Multi-Protocol Label Switching (MPLS) Traffic
Engineered Label Switched Paths (TE-LSPs). [RFC3209] specifies Engineered Label Switched Paths (TE-LSPs). [RFC3209] specifies
several additional conditions that trigger the sending of an RSVP several additional conditions that trigger the sending of a RSVP
PathErr message for which new error codes and error values have been PathErr message for which new error codes and error values have been
defined that extend the list defined in [RFC2205]. The exact defined that extend the list defined in [RFC2205]. The exact
circumstances under which such PathErr messages are sent are defined circumstances under which a TE LSP is preempted and such PathErr
in [RFC3209] and will not be repeated here. messages are sent are defined in [RFC3209] and will not be repeated
here.
Values for the Error Code and Error Value fields defined in Values for the Error Code and Error Value fields defined in
[RFC2205], [RFC3209], and other documents are maintained in a [RFC2205], [RFC3209], and other documents are maintained in a
registry by the IANA. A full list can be seen at Section 5. The registry by the IANA.
error conditions fall into two categories: - fatal errors represent
disruptive conditions for a TE LSP, - non-fatal errors are non- The error conditions fall into two categories:
disruptive conditions which have occurred for this TE LSP.
Additionally, PathErr messages may be used in two circumstances: - o Fatal errors represent disruptive conditions for a TE LSP,
during TE LSP establishment, - after a TE LSP has been successfully
established. Nodal behavior is dependent on which combination of the o Non-fatal errors are non-disruptive conditions which have occurred
four cases listed above applies. The following sections describe the for this TE LSP
expected behavior at nodes that detect (and therefore report using
PathErr messages) errors, and at nodes that receive PathErr messages. Additionally, PathErr messages may be used in two circumstances:
This text is a clarification and re-statement of the procedures set
out in [RFC3209] and does not define any new behavior. Section 2 o During TE LSP establishment,
provides a list of the currently defined PathErr Error Codes and
Error Values and indicates for each whether it is fatal or non-fatal. o After a TE LSP has been successfully established.
Nodal behavior is dependent on which combination of the four cases
listed above applies. The following sections describe the expected
behavior at nodes that perform a preemption action for a TE LSP (and
therefore report using error PathErr messages), and at nodes that
receive PathErr messages. This text is a clarification and re-
statement of the procedures set out in [RFC3209] and does not define
any new behavior.
1.1. Behavior at Detecting Nodes 1.1. Behavior at Detecting Nodes
In the case of fatal errors, the detecting node must send a PathErr In the case of fatal errors, the detecting node must send a PathErr
message reporting the error condition, and must clear the message reporting the error condition, and must clear the
corresponding Path and Resv (control plane) states. A direct corresponding Path and Resv (control plane) states. A direct
implication is that the data plane resources of such a TE LSP are implication is that the data plane resources of such a TE LSP are
also released, thus resulting in traffic disruption. It should be also released, thus resulting in traffic disruption. It should be
noted, however, that in fatal error cases, the LSP has usually noted, however, that in fatal error cases, the LSP has usually
already failed in the data plane, and traffic has already been already failed in the data plane, and traffic has already been
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the TE LSP. The message receiver should do likewise before the TE LSP. The message receiver should do likewise before
forwarding the message, but may retain state and clear the flag forwarding the message, but may retain state and clear the flag
before forwarding the message. before forwarding the message.
1.3. Data Plane Behavior 1.3. Data Plane Behavior
Any node clearing either or both the Path or the Resv state of a TE Any node clearing either or both the Path or the Resv state of a TE
LSP MUST also free up the data plane resources allocated to the LSP MUST also free up the data plane resources allocated to the
corresponding TE LSP. corresponding TE LSP.
2. IANA Considerations 2. RSVP PathErr Messages For a Preempted TE LSP
IANA maintains a registry of RSVP Error Codes and Error Values at Two Error-code can be used to report a preempted TE LSPs:
Section 5. The registry is labeled "Resource ReSerVation Protocol
(RSVP) Parameters" / "Error Codes and Values" IANA is requested to
add a column to this registry to indicate for each Error Code / Error
Value combination whether the error reported constitutes a fatal or
non-fatal error condition if the error is seen in an MPLS-TE system.
It is suggested that the column in headed "MPLS-TE Fatal" and contain
one of three values: Yes - The error condition represents a fatal
condition as described in this document when applied to an MPLS TE
LSP. No - The error condition represents a non-fatal condition as
described in this document when applied to an MPLS TE LSP. N/A - The
error condition cannot be applied to an MPLS TE LSP. IANA should
require that all new assignments from this registry provide
information in this column. In order to update this registry for the
creation of this column, the table below supplies the setting of the
column for each existing entry in the registry. IANA is requested to
transfer this information into the registry. Note that only the
Error Code and Error Value numbers are supplied here. No change to
any of the other registry fields is implied.
Error code Error Value Reference MPLS-TE Fatal o As defined in [RFC2750]:Error Code=2: "Policy Control Failure",
------------+--------------+--------------+-------------- Error Value=5 "Flow was preempted"
0 Any [RFC2205] N/A
1 Any [RFC2205] N/A o As defined in [RFC2205], Error Code=12: "Service preempted"
2 5 [RFC2750] Yes
100 [RFC3476] N/A In both cases, these are fatal errors.
101 [RFC3476] N/A
102 [RFC4495] N/A
Any other [RFC2205] N/A
3 Any [RFC2205] N/A
4 Any [RFC2205] N/A
5 Any [RFC2205] Yes
6 Any [RFC2205] N/A
7 Any [RFC2205] N/A
8 Any [RFC2205] N/A
9 Any [RFC2205] N/A
10 Any [RFC2205] N/A
11 Any [RFC2205] N/A
12 Any [RFC2205] N/A
13 Any [RFC2205]
14 Any [RFC2205]
15 Any [RFC2205] N/A
16 Any [RFC2205] N/A
17 Any [RFC2205] N/A
18 Any [RFC2205] N/A
19 Any [RFC2205] N/A
20 Any [RFC2205] N/A
21 Any [RFC2205]
22 Any [RFC2205]
23 Any [RFC2205]
24 1 [RFC3209] Yes
2 [RFC3209] Yes
3 [RFC3209] Yes
4 [RFC3209] Yes
5 [RFC3209] Yes
6 [RFC3209] Yes
7 [RFC3209] Yes
8 [RFC3209] Yes
9 [RFC3209] Yes
10 [RFC3209] Yes
11 [RFC3473] Yes
12 [RFC3473] Yes
13 [RFC3473] Yes
14 [RFC3473] Yes
15 [RFC3473] Yes
16 [RFC3473] Yes
100 [RFC3476] N/A
101 [RFC3476] N/A
102 [RFC3476] N/A
103 [RFC3474] N/A
104 [RFC3474] N/A
105 [RFC3474] N/A
106 [RFC3474] N/A
25 1 [RFC3209] No
2 [RFC3209] No
3 [RFC3209] No
4 [RFC3473] No
5 [RFC3473] No
6 [draft-ietf-ccamp-loose-path-reopt] No
7 [draft-ietf-ccamp-loose-path-reopt] No
8 [draft-ietf-ccamp-loose-path-reopt] No
26 Any [RFC3175] N/A
27 Any [RFC3270] N/A
28 Any [RFC4124] Yes
29 Any [RFC4420]
30 Any [RFC4420]
3. Security Considerations 3. Security Considerations
This document does not define any new procedures, but clarifies those This document does not define any new procedures, but clarifies those
defined in other documents where security considerations are already defined in other documents where security considerations are already
specified. This document does not raise specific security issues specified. This document does not raise specific security issues
beyond those of existing MPLS-TE. By clarifying the procedures, this beyond those of existing MPLS-TE. By clarifying the procedures, this
document reduces the security risk introduced by non-conformant document reduces the security risk introduced by non-conformant
implementations. implementations.
4. Acknowledgements 4. Acknowledgements
The author would like to thank Carol Iturralde, Ashok Narayanan, Rom The author would like to thank Carol Iturralde, Ashok Narayanan, Rom
Reuther and Reshad Rahman. Reuther and Reshad Rahman.
5. URLs 5. Normative References
[IANA-URL] http://www.iana.org/numbers.html
6. Normative References
[I-D.ietf-ccamp-loose-path-reopt]
Vasseur, J., "Reoptimization of Multiprotocol Label
Switching (MPLS) Traffic Engineering (TE) loosely routed
Label Switch Path (LSP)",
draft-ietf-ccamp-loose-path-reopt-02 (work in progress),
February 2006.
[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.
[RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. [RFC2205] Braden, B., 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, September 1997. Functional Specification", RFC 2205, September 1997.
[RFC2750] Herzog, S., "RSVP Extensions for Policy Control", [RFC2750] Herzog, S., "RSVP Extensions for Policy Control",
RFC 2750, January 2000. RFC 2750, January 2000.
[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, December 2001. Tunnels", RFC 3209, December 2001.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic (GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC4495] Polk, J. and S. Dhesikan, "A Resource Reservation Protocol
(RSVP) Extension for the Reduction of Bandwidth of a
Reservation Flow", RFC 4495, May 2006.
Authors' Addresses Authors' Addresses
JP Vasseur (editor) JP Vasseur (editor)
Cisco Systems, Inc Cisco Systems, Inc
1414 Massachusetts Avenue 1414 Massachusetts Avenue
Boxborough, MA 01719 Boxborough, MA 01719
USA USA
Email: jpv@cisco.com Email: jpv@cisco.com
skipping to change at page 9, line 4 skipping to change at page 7, line 4
1414 Massachusetts Avenue 1414 Massachusetts Avenue
Boxborough, MA 01719 Boxborough, MA 01719
USA USA
Email: swallow@cisco.com Email: swallow@cisco.com
Adrian Farrel Adrian Farrel
Old Dog Consulting Old Dog Consulting
Email: adrian@olddog.co.uk Email: adrian@olddog.co.uk
Ina Minei
Juniper Networks
1194 North Mathilda Ave.
Sunnyvale, 94089
Email: ina@juniper.net
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
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