Network Working Group Eric Gray, Fong Liaw, John Yu Internet Draft Zaffire Expiration Date: February 2001 John Drake, Jonathan Lang Calient Networks Yakov Rekhter, George Swallow Cisco Systems Kireeti Kompella Juniper Networks Bala Rajagopolan Tellium Raj Jain Nayna Networks Osama Aboul-Maged Nortel Networks Greg Bernstein Ciena Zhensheng Zhang Sorrento Networks July, 2000 RSVP Extensions in Support of OIF Optical UNI Signaling draft-gray-mpls-rsvp-oif-uni-ext-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. 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. Abstract This draft defines a signaling mechanism based on RSVP-TE ([2]) to support an Optical User Network Interface (UNI). This effort is in part driven by work in the OIF as well as the recent draft on signaling requirements for the optical UNI ([3]), and is consistent with recent work on Generalized MPLS (see [4], [5], [6], and [7]). The main function of this draft is to identify the relevant mechanisms in RSVP-TE (including further extensions) to satisfy functional requirements for an Optical UNI. This draft reflects ongoing work at the Optical Interworking Forum (OIF), however, not all of the concepts/requirements have been approved by the OIF. Gray, et al Page 01 1. Introduction There has recently been a significant effort amongst carriers, service providers, and vendors in the optical networking space to eliminate proprietary control protocols and develop a common control plane. The Optical Internetworking Forum (OIF) has initiated work on an Optical User-Network Interface (Optical UNI) as a step in this direction. Recently, a draft [3] was submitted to the IETF defining proposed requirements and abstract messages for the Optical UNI. This document describes how a signaling mechanism based on RSVP-TE [2] may be used for an Optical UNI. In particular, we identify the mechanisms already defined for RSVP-TE that can be used to satisfy the proposed requirements of [3]. This work is also based on recent Internet Drafts defining Generalized MPLS signaling (e.g. - [4]). 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 [8]. 2. Overview RSVP-TE is one of the candidate protocols described in [3] for Optical UNI signaling implementation. As part of this Optical UNI, the signaling protocol must have the capability to create, delete, and modify lightpaths across a network, as well as query the status of an existing lightpath. Most of these capabilities may be directly supported by re-using existing procedures, messages, and objects defined in RSVP-TE [2] and in Generalized MPLS Signaling [4]. This document further extends [2] and [4] to support Optical UNI signaling requirements as following: - Use of DREQ and DREP message and procedure as defined in [9] for Lightpath status enquiry and response. - Use of Message_ID and Message_Ack objects, Ack_desire flag, and Ack message as defined in [10] to support confirmation of Lightpath deletion and reliable messaging. - PathTear and ResvTear MUST be used to delete a lightpath. This specification does not specify procedures to support the following proposed requirements listed in [3]: - Concept of "indirect interface" as defined in [3]. It is envisioned that such a requirement can be better serviced via a network management station. - Different source and destination user groups. Instead, this specification allows specifying a single user group using resource affiliation defined in [2]. Gray, et al Page 02 - Procedures for client registration. 2.1 Use of RSVP-TE and Generalized MPLS signaling for Optical UNI 2.1.1 In-band and out-of-band signaling channels Optical UNI requires support of in-band and out-of-band signaling channels. The in-band signaling channel is supported by the use of a regular link; and the concept of out-of-band signaling channel is supported by the use of bundled links [8] where a bundled link consists of a control channel and one or more component links. When out-of-band signaling channel is used, the procedure, messages, and objects apply to a bundled link as defined in [4], [11], [12], and [5] shall be used. 2.1.2 Reliable messaging To support reliable messaging across the UNI, the Message_ID and Message_Ack objects, Ack message, and Ack desired flag of [10] MUST be used in UNI RSVP messages. Acknowledgements apply to hop-by-hop, as opposed to end-to-end, message delivery. 2.1.2 Lightpath creation Lightpath creation uses the procedure described in section 2.2 "Operation of LSP tunnels" of [2]. Additional objects and their use and procedure are defined in Sections 3 and 4 of [4]. 2.1.3 Lightpath modification Lightpath modification uses procedure as described in section 2.5 "Rerouting of Traffic Engineered Tunnels" of [2]. 2.1.4 Lightpath deletion Lightpath deletion can be done by either the client that originated or terminated the lightpath. The lightpath originator will use the PathTear message while the lightpath terminator will use the ResvTear message. Acknowledgement mechanisms of [10] MUST be used to provide confirmation. 2.1.5 Lightpath status enquiry and response Any client interested in the lightpath status shall send a Diagnostic Request (DREQ) message toward the termination end point of the lightpath. The DREQ message specifies the Session Object, Sender Template Object, and an ending node. Starting at the last hop of the lightpath, the DREQ message is sent along the lightpath toward the sender and start collecting information hop-by-hop in the DREQ. When the DREQ message reaches the ending node, the message type is changed to Diagnostic Reply (DREP) and forwarded to the original requestor node. The DREQ originator can select specific RSVP objects to be collected by including a DIAG_SELECT object in the DREQ message. The Gray, et al Page 03 full procedure of DREQ and DREP messages is described in [9]. 3. RSVP Message Extensions for OPTICAL UNI signaling In addition to objects defined in [2] and [4], new objects may need to be defined to address additional requirements. Additional objects defined in this specification are OPTIONAL with respect to RSVP and RSVP-TE. 3.1 Propagation Delay Object If a propagation delay is desired, the lightpath originator shall include a Propagation_Delay_object and an ADSPEC object in its Path Message for the lightpath. Network nodes along the lightpath must update the ADSPEC and compare the result with the propagation delay object. If the result is comformant, the node shall forward the Path message downstream. Otherwise, it shall generate a PathErr message carrying error code "XXX" (TBD) and discard the Path message. 3.2 Labels Generalized MPLS signaling [4] defines several types of labels that may be represented in a Generalized Label object. For Optical applications a label may be arbitrarily associated with all or part of a component link, or may be a superset of multiple component links. A common understanding of the meaning of a Generalized Label - in particular the meaning of the link ID portion of the Generalized Label - must exist between the user and the network across any Optical UNI. This common understanding may be dynamically derived (e.g. using LMP [5]), or it may be configured. This specification uses the Generalized Label, Generalized Label Request, Upstream Label, Suggested Label and Label Set objects defined in [4]. 4. RSVP objects related to OPTICAL signaling requirements Optical UNI signaling requirements [3] specify a set of attributes to be signaled during lightpath creation and modification. The following table summarizes the RSVP objects that are used to signaling a particular OPTICAL signaling attribute. Gray, et al Page 04 OPTICAL signaling attribute RSVP object ------------------------------+------------------------------- Light_Path ID | Session [2] Source termination point | Sender Template (or Session) [2] Destination termination point | Session [2] Source Termination Point Port | Label Set/Suggest Label [4] Destination Termination Label | Egress Label [4] Contract ID | Session Attribute/Name [2] Framing | Generalized Label Request [4] Bandwidth | Generalized Label Request [4] Transparency | Generalized Label Request [4] Directionality | Upstream Label [4] Service Level | Session Attribute [2] Diversity | Session Attribute [2] | and Generalized Label Request | Object [4] Return code | Error Spec Source user group ID | Session Attributes/LSP_TUNNEL_RA [2] Destination user group ID | Session Attributes/LSP_TUNNEL_RA [2] Propagation Delay | Propagation Delay (TBD) ------------------------------+--------------------------------- 5. RSVP messages related to OPTICAL UNI signaling 5.1 Path Message As described in [4], RSVP-TE signaling for support of lightpath creation allows for labels to be suggested by the upstream LSR that is sending a Path message. In addition, the upstream node may provide a label for use in bi-directional setup. The format for the Path message to be used for the OPTICAL UNI is given below. <Path Message> ::= <Common Header> [ <INTEGRITY> ] <SESSION> <RSVP_HOP> [ <TIME_VALUES> ] [ <EXPLICIT ROUTE> ] <GENERALIZED LABEL_REQUEST> [ <LABEL SET> | <SUGGESTED LABEL> ] [ <UPSTREAM LABEL> ] [ <SESSION_ATTRIBUTE> ] [ <POLICY_DATA> ... ] <sender descriptor> <sender descriptor> ::= <SENDER_TEMPLATE> <SENDER TSPEC> [ <ADSPEC> <PROPAGATION DELAY> ] [ <RECORD_ROUTE> ] The EXPLICIT ROUTE object may be included to provide an egress label ([4]). Additional explicit hops included in the EXPLICT ROUTE object MAY be ignored by the Network in the Optical UNI. Similarly, the RECORD ROUTE object MAY be ignored by the Network side of the Optical UNI. Gray, et al Page 05 5.2 Resv Message RSVP-TE signaling support of the lightpath creation response is via the OPTICAL UNI Resv message. The format for the OPTICAL UNI Resv Message is as shown below. <Resv Message> ::= <Common Header> [ <INTEGRITY> ] <SESSION> <RSVP_HOP> [ <TIME_VALUES> ] [ <RESV_CONFIRM> ] [ <SCOPE> ] [ <POLICY_DATA> ... ] <STYLE> <flow descriptor list> <flow descriptor list> ::= <FF flow descriptor list> | <SE flow descriptor> <FF flow descriptor list> ::= <FLOWSPEC> <FF flow descriptor> | <FF flow descriptor list> <FF flow descriptor> <FF flow descriptor> ::= [ <FLOWSPEC> ] <FILTER_SPEC> <GENERALIZED LABEL> [ <RECORD_ROUTE> ] <SE flow descriptor> ::= <FLOWSPEC> <SE filter spec list> <SE filter spec list> ::= <SE filter spec> | <SE filter spec list> <SE filter spec> <SE filter spec> ::= <FILTER SPEC> <GENERALIZED LABEL> [ <RECORD ROUTE> ] 3.4 PathTear Message The lightpath origination node uses a PathTear message to explicitly delete a lightpath. The acknowledgement procedures of [10] are used to provide confirmation. Receiving of a MESSAGE_ID_ACK object of a PathTear message SHALL be interpreted to mean that the downstream node has cleared its state associated with the specified lightpath, but not to mean a confirmation of an end-to-end lightpath deletion. If a MESSAGE_ID_ACK object of a PathTear Message cannot be piggybacked in an pending RSVP message immediately, a downstream node SHALL generate a Notify message including the MESSAGE_ID_ACK object to its upstream node. This allows a faster confirmation for the PathTear message. 5.4 ResvTear Message A lightpath termination node uses ResvTear Message to explicitly delete a lightpath. The acknowledgement procedures of [10] are used to provide confirmation. Receiving of a MESSAGE_ID_ACK object of a ResvTear message SHALL be interpreted to mean that the upstream node has cleared its state associated with the specified lightpath, but not to mean a confirmation of an end- Gray, et al Page 06 to-end lightpath deletion. If a MESSAGE_ID_ACK object of a ResvTear Message cannot be piggybacked in a pending RSVP message immediately, an upstream node SHALL generate a Notify message including the MESSAGE_ID_ACK object to its upstream node. This allows a faster confirmation for the ResvTear message. 5.5 Notify Message The Notify message can be generated at any time to allow expedited notification of change in the status of a lightpath. Consequently, both the user and network sides of the Optical UNI MUST be prepared to receive a Notify message. The format of the Notify message is given in [4]. 5.6 Diagnostic (DREQ) Message The DREQ Message is used to initiate Lightpath Status Enquiry required by [3]. The format of the Diagnostic Request (DREQ) message is given in [9]. Refer to [9] for full procedures on how to handle DREQ messages. 5.7 Diagnostic Reply (DREP) Message The DREP Message is used to send the collected lightpath status to originator of the DREQ message. It has the same format as the DREQ message. Refer to [9] for procedures on how to forward a DREP message. 6. Security Considerations TBD 7. References [1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. [2] Awduche, D. O., Berger, L., Gan, D.-H., Li, T., Swallow, G., Srinivasan, V., "Extensions to RSVP for LSP Tunnels", Work in Progress (Internet Draft), draft-ietf-mpls-rsvp-lsp-tunnel-06.txt, July 2000. [3] Aboul-Magd, O., Aparicio, O., Barry, R., Bernstein, G., Jain, R., Jia, L., Dulepet, R., Lazer, M., Yates, J., Pendarakis, D., Rajagopalan, B., Rennison, R., Xu, Y., Xue, Y., Yu, J. and Zhang, Z., "Signaling Requirements at the Optical UNI", Work in Progress (Internet Draft), July 2000. [4] Ashwood-Smith, P., Fan, Y., Banerjee, A., Drake, J., Lang, J., Berger, L., Bernstein, G., Kompella, K., Mannie, E., Rajagopalan, B., Saha, S., Tang, Z., Rekhter, Y. and Sharma, V., "Generalized MPLS - Signaling Functional Description", Work in Progress (Internet Draft), draft-ashwood-generalized-mpls-signaling-00.txt, June 2000. Gray, et al Page 07 [5] Lang, J.P., Mitra, K., Drake, J., Kompella, K., Rekhter, Y., Saha, D., Berger, L., Basak, D., and Sandick, H., "Link Management Protocol (LMP)", Work in Progress (Internet Draft), draft-lang-mpls-lmp-01.txt, July 2000. [6] Kompella, K., Rekhter, Y., Banerjee, A., Drake, J., Bernstein, G., Fedyk, D., Mannie, E., Saha, D., and Sharma, V., "OSPF Extensions in Support of MPL(ambda)S", Work in Progress (Internet Draft), draft-kompella-ospf-ompls-extensions-00.txt, July 2000. [7] Kompella, K., Rekhter, Y., Banerjee, A., Drake, J., Bernstein, G., Fedyk, D., Mannie, E., Saha, D., and Sharma, V., "IS-IS Extensions in Support of MPL(ambda)S", Work in Progress (Internet Draft), draft-kompella-ospf-ompls-extensions-00.txt, July 2000. [8] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119 (BCP 14), March 1997. [9] Terzis, A., etal., "RSVP Diagnostic Messages", RFC 2745, January 2000. [10] Berger, L. etal., "RSVP Refresh Overhead Reduction Extensions", Work in Progress (Internet Draft), June 2000. [11] Kompella, K. etal., "Link Bundling in MPLS Traffic Engineering", Work in Progress (Internet Draft), July 2000. [12] Kompella, K. etal., "Traffic Engineering with Unnumbered Links", Work in Progress (Internet Draft), July 2000. 8. Acknowledgments TBD 9. Author's Addresses Eric Gray Zaffire, Inc. 2630 Orchard Parkway San Jose, CA 95134 Email: egray@zaffire.com Fong Liaw Zaffire, Inc. 2630 Orchard Parkway San Jose, CA 95134 Email: fliaw@zaffire.com John Yu Zaffire, Inc. 2630 Orchard Parkway San Jose, CA 95134 Email: jzyu@zaffire.com Gray, et al Page 08 Jonathan Lang Calient Networks, Inc. 25 Castilian Goleta, CA 93117 Email: jplang@calient.net John Drake Calient Networks, Inc. 25 Castilian Goleta, CA 93117 Email: jdrake@calient.net George Swallow Cisco Systems, Inc. 250 Apollo Drive Chelmsford, MA 01824 Email: swallow@cisco.com Yakov Rekhter Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 Email: yakov@cisco.com Kireeti Kompella Juniper Networks, Inc. 385 Ravendale Drive Mountain View, CA 94043 Email: kireeti@juniper.net Bala Rajagopolan Tellium, Inc. 2 Crescent Place Ocean Port, NJ 07757 Email: braja@tellium.com Raj Jain Nayna Networks, Inc. 157 Topaz Street Milpitas, CA 95035 Email: raj@nayna.com Osama Aboul-Magd Nortel Networks PO Box 3511, Station C Ottawa, Ontario, Canada K1Y-4H7 Email: osmama@nortelnetworks.com Greg Bernstein Ciena Corporation, Core Switching Division 10201 Bubb Road Cupertino, CA 95014 Email: greg@ciena.com Gray, et al Page 09 Zhengsheng Zhang Sorrento Networks 9990 Mesa Rim Road San Diego, CA 92121 Email: zzhang@sorrentonet.com Gray, et al Page 10