Network Working Group H. Long, M.Ye Internet Draft Huawei Technologies Co., Ltd Intended status: Standards Track G. Mirsky Ericsson A.D'Alessandro Telecom Italia S.p.A H. Shah Ciena Expires: August 2016 February 19, 2016 OSPF Routing Extension for Links with Variable Discrete Bandwidth draft-ietf-ccamp-ospf-availability-extension-04.txt Abstract A network may contain links with variable discrete bandwidth, e.g., copper, radio, etc. The bandwidth of such links may change discretely in reaction to changing external environment. Availability is typically used for describing such links during network planning. This document introduces an optional ISCD Availability sub-TLV in OSPF routing protocol. This extension can be used for route computation in a network that contains links with variable discrete bandwidth. Status of this Memo This Internet-Draft is submitted 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 Long, et al. Expires August 19, 2016 [Page 1] Internet-Draft OSPF -- Availability extension February 2016 This Internet-Draft will expire on August 19, 2016. Copyright Notice Copyright (c) 2016 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction ................................................ 3 2. Overview .................................................... 3 3. Extension to OSPF Routing Protocol........................... 4 3.1. ISCD Availability sub-TLV............................... 4 3.2. Signaling Process....................................... 5 4. Security Considerations...................................... 5 5. IANA Considerations ......................................... 5 6. References .................................................. 5 6.1. Normative References.................................... 5 6.2. Informative References.................................. 6 7. Acknowledgments ............................................. 6 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 RFC-2119 [RFC2119]. The following acronyms are used in this draft: OSPF Open Shortest Path First PSN Packet Switched Network SNR Signal-to-noise Ratio LSP Label Switched Path Long, et al. Expires August 19, 2016 [Page 2] Internet-Draft OSPF -- Availability extension February 2016 ISCD Interface Switching Capacity Descriptor LSA Link State Advertisement 1. Introduction Some data communication technologies, e.g., microwave, and copper, allow seamless change of maximum physical bandwidth through a set of known discrete values. The parameter availability [G.827, F.1703, P.530] is often used to describe the link capacity during network planning. The availability is a time scale that the requested bandwidth is ensured. Assigning different availability classes to different types of service over such kind of links provides more efficient planning of link capacity. To set up an LSP across these links, availability information is required for the nodes to verify bandwidth satisfaction and make bandwidth reservation. The availability information should be inherited from the availability requirements of the services expected to be carried on the LSP. For example, voice service usually needs ''five nines'' availability, while non-real time services may adequately perform at four or three nines availability. Since different service types may need different availabilities guarantees, multiple pairs may be required when signaling. The signaling extension for links with discrete bandwidth is defined in [ASTE]. For the route computation, the availability information should be provided along with bandwidth resource information. In this document, an extension on Interface Switching Capacity Descriptor (ISCD) [RFC4202] for availability information is defined to support in routing signaling. The extension reuses the reserved field in the ISCD and also introduces an optional Availability sub-TLV. If there is a hop that cannot support the Availability sub-TLV, the Availability sub-TLV should be ignored. 2. Overview A node which has link(s) with variable bandwidth attached should contain a information list in its OSPF TE LSA messages. The list provides the information that how much bandwidth a link can support for a specified availability. This information is used for path calculation by the node(s). To setup a label switching path (LSP), a node may collect link information which is spread in OSPF TE LSA messages by network nodes to get know about the network topology, calculate out an LSP route Long, et al. Expires August 19, 2016 [Page 3] Internet-Draft OSPF -- Availability extension February 2016 based on the network topology and send the calculated LSP route to signaling to initiate a PATH/RESV message for setting up the LSP. Availability information is required to carry in the signaling message to better utilize the link bandwidth. The signaling extension for availability can be found in [ASTE]. 3. Extension to OSPF Routing Protocol 3.1. ISCD Availability sub-TLV The Interface Switching Capacity Descriptor (ISCD) sub-TLV is defined in Section 1.4 of [RFC 4203]. The ISCD Availability sub-TLV is defined in this document as a sub-TLV of ISCD. The Switching Capability specific information field of ISCD MAY include one or more ISCD Availability sub-TLV(s). The ISCD Availability sub-TLV has the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Availability level | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LSP Bandwidth at Availability level n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: 0x01, 16 bits; Length: 16 bits; Availability level: 32 bits This field is a 32-bit IEEE floating point number which describes the decimal value of availability guarantee of the switching capacity in the ISCD object which has the AI value equal to Index of this sub-TLV. The value MUST be less than 1. LSP Bandwidth at Availability level n: 32 bits This field is a 32-bit IEEE floating point number which describes the LSP Bandwidth at a certain Availability level which was described in the Availability field. Long, et al. Expires August 19, 2016 [Page 4] Internet-Draft OSPF -- Availability extension February 2016 3.2. Signaling Process A node which has link(s) with variable bandwidth attached SHOULD contain one or more ISCD Availability sub-TLVs in its OSPF TE LSA messages. Each ISCD Availability sub-TLV provides the information about how much bandwidth a link can support for a specified availability. This information SHOULD be used for path calculation by the node(s). A node that doesn't support ISCD Availability sub-TLV SHOULD ignore ISCD Availability sub-TLV. 4. Security Considerations This document does not introduce new security considerations to the existing OSPF protocol. 5. IANA Considerations This document introduces an Availability sub-TLV of the ISCD sub-TLV of the TE Link TLV in the TE Opaque LSA for OSPF v2. This document proposes a suggested value for the Availability sub-TLV; it is recommended that the suggested value be granted by IANA. Initial values are as follows: Type Length Format Description --- ---- ------------------ ----------- 0 - Reserved Reserved value 0x01 8 see Section 3.2 Availability 6. References 6.1. Normative References [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005. [ASTE] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., ''Ethernet Traffic Parameters with Availability Information'', Work in Progress, June, 2015 Long, et al. Expires August 19, 2016 [Page 5] Internet-Draft OSPF -- Availability extension February 2016 6.2. Informative References [RFC2210] Wroclawski, J., ''The Use of RSVP with IETF Integrated Services'', RFC 2210, September 1997. [RFC2119] Bradner, S., ''Key words for use in RFCs to Indicate Requirement Levels'', RFC 2119, March 1997 [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. [RFC4202] Kompella, K. and Rekhter, Y. (Editors), ''Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, October 2005. [MCOS] Minei, I., Gan, D., Kompella, K., and X. Li, "Extensions for Differentiated Services-aware Traffic Engineered LSPs", Work in Progress, June 2006. [G.827] ITU-T Recommendation, ''Availability performance parameters and objectives for end-to-end international constant bit- rate digital paths'', September, 2003. [F.1703] ITU-R Recommendation, ''Availability objectives for real digital fixed wireless links used in 27 500 km hypothetical reference paths and connections'', January, 2005. [P.530] ITU-R Recommendation,'' Propagation data and prediction methods required for the design of terrestrial line-of- sight systems'', February, 2012 [EN 302 217] ETSI standard, ''Fixed Radio Systems; Characteristics and requirements for point-to-point equipment and antennas'', April, 2009 7. Acknowledgments The authors would like to thank Lou Berger for his comments on the document. Long, et al. Expires August 19, 2016 [Page 6] Internet-Draft OSPF -- Availability extension February 2016 Authors' Addresses Hao Long Huawei Technologies Co., Ltd. No.1899, Xiyuan Avenue, Hi-tech Western District Chengdu 611731, P.R.China Phone: +86-18615778750 Email: longhao@huawei.com Min Ye Huawei Technologies Co., Ltd. No.1899, Xiyuan Avenue, Hi-tech Western District Chengdu 611731, P.R.China Email: amy.yemin@huawei.com Greg Mirsky Ericsson Email: gregory.mirsky@ericsson.com Alessandro D'Alessandro Telecom Italia S.p.A Email: alessandro.dalessandro@telecomitalia.it Himanshu Shah Ciena Corp. 3939 North First Street San Jose, CA 95134 US Email: hshah@ciena.com Long, et al. Expires August 19, 2016 [Page 7]