--- 1/draft-ietf-mpls-3209-patherr-00.txt 2008-02-08 21:12:16.000000000 +0100 +++ 2/draft-ietf-mpls-3209-patherr-01.txt 2008-02-08 21:12:16.000000000 +0100 @@ -1,21 +1,23 @@ Networking Working Group JP. Vasseur, Ed. Internet-Draft George. Swallow Intended status: Best Current Cisco Systems, Inc Practice Adrian. Farrel -Expires: November 4, 2007 Old Dog Consulting - May 3, 2007 +Expires: August 11, 2008 Old Dog Consulting + Ina. Minei + Juniper Networks + February 8, 2008 Node behavior upon originating and receiving Resource ReserVation Protocol (RSVP) Path Error message - draft-ietf-mpls-3209-patherr-00.txt + draft-ietf-mpls-3209-patherr-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -26,65 +28,66 @@ 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on November 4, 2007. + This Internet-Draft will expire on August 11, 2008. Copyright Notice - Copyright (C) The IETF Trust (2007). + Copyright (C) The IETF Trust (2008). Abstract The aim of this document is to describe a common practice with regard 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 Path Error message for a particular Multi-Protocol Label - Switching - Traffic Engineering (MPLS-TE) Label Switched Path (LSP). - - This document does not define any new protocol extensions. + (RSVP) Traffic Engineering (TE) Path Error message and to the + behavior of a node receiving an RSVP Path Error message for a + preempted Multi-Protocol Label Switching (MPLS) Traffic Engineering + Label Switched Path (TE LSP). This document does not define any new + protocol extensions. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Table of Contents 1. Protocol behavior . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Behavior at Detecting Nodes . . . . . . . . . . . . . . . . 4 1.2. Behavior at Receiving Nodes . . . . . . . . . . . . . . . . 4 1.3. Data Plane Behavior . . . . . . . . . . . . . . . . . . . . 5 - 2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 - 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 - 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 - 5. URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 6. Normative References . . . . . . . . . . . . . . . . . . . . . 7 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 - Intellectual Property and Copyright Statements . . . . . . . . . . 9 + 2. RSVP PathErr Messages For a Preempted TE LSP . . . . . . . . . 5 + 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 + 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 + 5. Normative References . . . . . . . . . . . . . . . . . . . . . 6 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 + Intellectual Property and Copyright Statements . . . . . . . . . . 8 1. Protocol behavior [RFC2205] defines two RSVP error message types: PathErr and ResvErr that are generated when an error occurs. Path Error Messages (PathErr) are used to report errors and travel upstream toward the head-end of the flow. Resv Error messages (ResvErr) travel 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 a Path message is routed through the network from the head-end to its tail-end. 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- end of the TE LSP (Traffic Engineering Label Switched Path). The format of the PathErr message as defined in [RFC2205] is as follows: @@ -98,42 +101,51 @@ [ ] The ERROR_SPEC object includes the IP address of the node that detected the error (Error Node Address), and specifies the error through two fields. The Error Code field encodes the category of the error, for example, Policy Control Failure or Unknown object class. The Error Value field qualifies the error code to indicate the error with more precision. [RFC3209] extends RSVP as defined in [RFC2205] for the management of Multi-Protocol Label Switching (MPLS) Traffic 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 defined that extend the list defined in [RFC2205]. The exact - circumstances under which such PathErr messages are sent are defined - in [RFC3209] and will not be repeated here. + circumstances under which a TE LSP is preempted and such PathErr + messages are sent are defined in [RFC3209] and will not be repeated + here. Values for the Error Code and Error Value fields defined in [RFC2205], [RFC3209], and other documents are maintained in a - registry by the IANA. A full list can be seen at Section 5. The - error conditions fall into two categories: - fatal errors represent - disruptive conditions for a TE LSP, - non-fatal errors are non- - disruptive conditions which have occurred for this TE LSP. - Additionally, PathErr messages may be used in two circumstances: - - during TE LSP establishment, - 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 detect (and therefore report using - PathErr messages) errors, 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. Section 2 - provides a list of the currently defined PathErr Error Codes and - Error Values and indicates for each whether it is fatal or non-fatal. + registry by the IANA. + + The error conditions fall into two categories: + + o Fatal errors represent disruptive conditions for a TE LSP, + + o Non-fatal errors are non-disruptive conditions which have occurred + for this TE LSP + + Additionally, PathErr messages may be used in two circumstances: + + o During TE LSP establishment, + + 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 In the case of fatal errors, the detecting node must send a PathErr message reporting the error condition, and must clear the corresponding Path and Resv (control plane) states. A direct implication is that the data plane resources of such a TE LSP are also released, thus resulting in traffic disruption. It should be noted, however, that in fatal error cases, the LSP has usually already failed in the data plane, and traffic has already been @@ -163,158 +175,65 @@ the TE LSP. The message receiver should do likewise before forwarding the message, but may retain state and clear the flag before forwarding the message. 1.3. Data Plane Behavior 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 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 - 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. + Two Error-code can be used to report a preempted TE LSPs: - Error code Error Value Reference MPLS-TE Fatal - ------------+--------------+--------------+-------------- - 0 Any [RFC2205] N/A - 1 Any [RFC2205] N/A - 2 5 [RFC2750] Yes - 100 [RFC3476] N/A - 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] + o As defined in [RFC2750]:Error Code=2: "Policy Control Failure", + Error Value=5 "Flow was preempted" + + o As defined in [RFC2205], Error Code=12: "Service preempted" + + In both cases, these are fatal errors. 3. Security Considerations This document does not define any new procedures, but clarifies those defined in other documents where security considerations are already specified. This document does not raise specific security issues beyond those of existing MPLS-TE. By clarifying the procedures, this document reduces the security risk introduced by non-conformant implementations. 4. Acknowledgements The author would like to thank Carol Iturralde, Ashok Narayanan, Rom Reuther and Reshad Rahman. -5. URLs - - [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. +5. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC2750] Herzog, S., "RSVP Extensions for Policy Control", RFC 2750, January 2000. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic 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 JP Vasseur (editor) Cisco Systems, Inc 1414 Massachusetts Avenue Boxborough, MA 01719 USA Email: jpv@cisco.com @@ -323,24 +242,30 @@ 1414 Massachusetts Avenue Boxborough, MA 01719 USA Email: swallow@cisco.com Adrian Farrel Old Dog Consulting Email: adrian@olddog.co.uk + Ina Minei + Juniper Networks + 1194 North Mathilda Ave. + Sunnyvale, 94089 + + Email: ina@juniper.net 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 contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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