Network Working Group D. Li Internet Draft Huawei Updates: RFC4204 Category: Standards Track Expires: March 2010 September 16, 2009 Behavior Negotiation in Link Management Protocol draft-li-ccamp-lmp-behavior-negotiation-00.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." 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. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Li Expires March 2010 [Page 1] draft-li-ccamp-lmp-behavior-negotiation-00.txt September 2009 Abstract The Link Management Protocol (LMP) is used to coordinate the properties, use, and faults of data links in Generalized Multiprotocol Label Switching (GMPLS) networks. Various proposals have been advanced to provide extensions to the base LMP specification. This document provides a generic procedure for LMP implementations that do not recognize or do not support any one of these extensions. Conventions used in this document 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 [RFC2119]. Table of Contents 1. Introduction.................................................2 2. LMP Behavior Negotiation Procedure...........................3 3. Security Considerations......................................4 4. IANA Considerations..........................................5 5. Acknowledgments..............................................5 6. References...................................................5 6.1. Normative References....................................5 6.2. Informative References..................................5 7. Author's Address.............................................6 1. Introduction The Link Management Protocol (LMP) [RFC4204] is being successfully deployed in Generalized Multiprotocol Label Switching (GMPLS) networks in the field. New LMP behaviors and protocol extensions are being introduced in a number of IETF documents. In the network, if one GMPLS Label Switching Router (LSR) supports a new behavior or protocol extension, but its peer LSR does not, it is necessary to have a protocol mechanism for resolving issues that may arise. It is also beneficial to have a protocol mechanism to discover the capabilities of peer LSRs. There is no such procedure defined in the base LMP specification [RFC4204], so this document defines how to handle LMP extensions both at legacy LSRs and at upgraded LSRs that communicate with legacy LSRs. In [RFC4204], the basic behaviors have been defined around the use of the standard LMP message, which includes Config, Hello, Verify, Test, Li Expires March 2010 [Page 2] draft-li-ccamp-lmp-behavior-negotiation-00.txt September 2009 LinkSummary, ChannelStatus. Per [RCF4204], these behaviors MUST be supported when the LMP is implemented, and the message types from 1 to 20 are used for these behaviors. In [RFC4207], the SONET/SDH technology-specific information for LMP is defined. The TRACE behavior is added to LMP, and the message types from 21 to 31 were defined for the TRACE function. In [RFC4209], extensions to LMP are defined to allow it to be used between a peer node and an adjacent optical line system (OLS). The LMP object class type and sub-object class name have been extended to support DWDM behavior. In [DCSC], the data channel consistency check behavior is defined, the message types from 32 to 34 are used for this behavior. This document describes the behavior negotiation procedure to make sure both LSRs understand the LMP messages being exchanged between peers. 2. LMP Behavior Negotiation Procedure The Config message is used in the control channel negotiation phase of LMP [RC4204]. The LMP behavior negotiation procedure is defined in this document as an addition at this phase. The Config message is defined in Section 12.3.1 of [RFC4204] and carries the object (class name 6) as defined in Section 13.6 of [RFC4204]. Multiple objects (each with a different Class Type) MAY be present on a Config message in which case all of the objects MUST be processed. Two class types have been defined. o C-Type = 1, HelloConfig, defined in [RFC4204] o C-Type = 2, LMP_WDM_CONFIG, defined in [RFC4209] This document defines a third C-Type with value 3 (TBD by IANA) to report and negotiate new and future LMP extensions and behaviors. The format of the new CONFIG Class is defined as follows: o C-Type = 3, ENHANCED_BEHAVIOR_CONFIG Li Expires March 2010 [Page 3] draft-li-ccamp-lmp-behavior-negotiation-00.txt September 2009 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|D| (Reserved) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ S: 1 bit This bit indicates support for the SONET/SDH TRACE messages defined in [RFC4207]. D: 1 bit This bit indicates support for the Data Channel Status Confirmation messages defined in [DCSC]. Further bits may be defied in future documents. The Reserved field MUST be sent as zero and MUST NOT be ignored on receipt. This allows the detection of supported/unsupported LMP behaviors. For example, if a bit is set that is not recognized, then a ConfigNack message MUST be sent with a CONFIG object that represents the supported LMP behaviors. An LSR that receives a Config message containing a object with a C-Type that it does not recognize MUST respond with a ConfigNack message as described in [RFC4204]. Thus, legacy LMP nodes that do not support the ENHANCED_BEHAVIOR_CONFIG C-Type defined in this document will respond with a ConfigNack message. 3. Security Considerations [RFC4204] describes how LMP messages between peers can be secured, and these measures are equally applicable to messages carrying the new object defined in this document. The operation of the procedures described in this document does not of itself constitute a security risk since they do not cause any change in network state. It would be possible, if the messages were intercepted or spoofed to cause bogus alerts in the management plane, or to cause LMP peers to consider that they could or could not operate protocol extensions, and so the use of the LMP security measures are RECOMMENDED. Li Expires March 2010 [Page 4] draft-li-ccamp-lmp-behavior-negotiation-00.txt September 2009 4. IANA Considerations IANA maintains the "Link Management Protocol (LMP)" registry which has a subregistry called "LMP Object Class name space and Class type (C-Type)". IANA is requested to make an assignment from this registry as follows: 6 CONFIG [RFC4204] CONFIG Object Class type name space C-Type Description Reference ------ ------------------------ --------- 3 ENHANCED_BEHAVIOR_CONFIG [This.I-D] 5. Acknowledgments Thanks to Adrian Farrel and Lou Berger for their useful comments. 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4204] J. Lang, Ed., "Link Management Protocol (LMP)", RFC 4204, October 2005. [RFC4207] J. Lang, Ed., "Synchronous Optical Network (SONET)/ Synchronous Digital Hierarchy (SDH) Encoding for Link Management Protocol (LMP) Test Messages", RFC 4207, October 2005. [RFC4209] A. Fredette, Ed., "Link Management Protocol (LMP) for Dense Wavelength Division Multiplexing (DWDM) Optical Line Systems", RFC 4209, October 2005. 6.2. Informative References [DCSC] D. Li, Ed., "Data Channel Status Confirmation Extensions for the Link Management Protocol", draft-ietf-ccamp- confirm-data-channel-status-07.txt, September 2009 Li Expires March 2010 [Page 5] draft-li-ccamp-lmp-behavior-negotiation-00.txt September 2009 7. Author's Address Dan Li Huawei Technologies F3-5-B R&D Center, Huawei Base, Shenzhen 518129 China Phone: +86 755-289-70230 Email: danli@huawei.com Li Expires March 2010 [Page 6]