RSVP-TE Signaling Extension for Bandwidth availability
Author(s): Hao Long, Min Ye
Packet switching network usually contains links with variable bandwidth, e.g., copper, radio, etc. The bandwidth of such link is sensitive to external environment. Availability is typically used for describing the link during network planning. This document describes an...
Network Working Group H. Long Internet Draft M.Ye Intended status: Standards Track Huawei Technologies Co., Ltd Expires: August 2013 February 18, 2013 RSVP-TE Signaling Extension for Bandwidth availability draft-long-ccamp-rsvp-te-bandwidth-availability-00.txt Abstract Packet switching network usually contains links with variable bandwidth, e.g., copper, radio, etc. The bandwidth of such link is sensitive to external environment. Availability is typically used for describing the link during network planning. This document describes an extension for RSVP-TE signaling for setting up a LSP in a PSN network which contains variable bandwidth link by introducing an optional availability field in RSVP-TE signaling. 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 This Internet-Draft will expire on August 18, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. Long & Ye Expires August 18, 2013 [Page 1] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 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 ................................................ 2 2. Extension to RSVP-TE Signaling............................... 3 3. Extension to Routing Protocol................................ 6 4. Security Considerations...................................... 8 5. IANA Considerations ......................................... 8 6. References .................................................. 8 6.1. Normative References.................................... 8 6.2. Informative References.................................. 9 7. Acknowledgments ............................................. 9 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 [RFC 2119]. 1. Introduction The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473] specify the signaling message including the bandwidth request for setting up a label switching path in a PSN network. In some networks, there may be some links with variable bandwidth. For example, in mobile backhaul network, microwave links are very popular for providing connection of last hops. In case of heavy rain, to maintain the link connectivity, the microwave link will lower the modulation format since demodulating lower modulation format need lower signal-to-noise ratio (SNR). This is called adaptive modulation technology. However, lower modulation format also means lower link bandwidth. Similarly the cooper links may change their link bandwidth due to external interference. The parameter, availability [G.827, F.1703], is often used to describe the link capacity during network planning. A link may provide different bandwidth for different availability requirement. Long & Ye Expires August 18, 2013 [Page 2] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 To set up a LSP across such kind of 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. Since different service types may need different availabilities guarantee, multiple <availability, bandwidth> pairs may be required to be signaled. In addition, for the routing computation, the availability information should also be provided with bandwidth resource information. To fulfill LSP setup by signaling in these scenarios, this document specifies the following extensions: o A new SENDER_TSPEC object is defined which includes multiple bandwidth profiles with different availability. This object is an extension on the Ethernet SENDER_TSPEC defined by [RFC6003] which support multiple bandwidth profile TLVs, but limited in the scope of Ethernet. The extension uses the object generically, and amends availability information in the bandwidth profile TLV. o An extension on Interface Switching Capacity Descriptor (ISCD) [RFC4202] for availability information support in routing signaling. The extension reuses the reserved field in the ISCD and also introduces an optional availability sub-TLV. 2. Overview A PSN tunnel may span one or more links in a network. To setup a label switching path (LSP), a PE node may collect link information which is spread in routing message by network nodes, and calculate out a LSP route, and initiate a PATH/RESV signaling for setting up the LSP. In case that there is(are) link(s) with variable bandwidth in a network, a <bandwidth, availability> requirement list should be specified for a LSP. Each <bandwidth, availability> pair in the list means a bandwidth with specified availability is required. The list could be inherited from the result of service planning for the LSP. A node which has link(s) with variable bandwidth attached should contain a similar <bandwidth, availability> information list in its routing 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 PE node(s). Long & Ye Expires August 18, 2013 [Page 3] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 When a PE node initiates a PATH/RESV signaling for setting up the LSP, the PATH message should carry the <bandwidth, availability> requirement list as bandwidth request, and the intermediate node(s) will allocate the bandwidth resource for each availability requirement from the remained bandwidth with corresponding availability. An error message may be returned if any <bandwidth, availability> request cannot be satisfied. 3. Extension to RSVP-TE Signaling 3.1. SENDER_TSPEC Object The SENDER_TSPEC object (Class-Num = 12) 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length | Class-Num (12)| C-Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Class-Specific Information (Optional) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Class-Specific Information: 32 bits This field indicates the specific information for each C-Type. TLV (Type-Length-Value): The SENDER_TSPEC object MUST include at least one TLV and MAY include more than one TLV. 3.1.1. Bandwidth Profile TLV The Bandwidth Profile TLV has the following format. Long & Ye Expires August 18, 2013 [Page 4] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Profile | Index | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... ... | ~ Traffic Parameters ~ | ... ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: TBD, 16 bits; Length: 16 bits; Profile: 8 bits This field is defined as a bit vector of binary flags. The following flags are defined: Flag 3 (bit 2): Availability Flag (AF) When The Flag 3 is set to value 1, there is an availability sub-TLV included in this Bandwidth Profile TLV. The 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type (2 octets): TBD Length (2 octets): 4 Availability (4 octets): a 32-bit floating number describes availability requirement for this bandwidth request. The value must be less than 1. Index: 8 bits See [RFC6003] section 4.1. Long & Ye Expires August 18, 2013 [Page 5] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 Traffic Parameters: This field includes the traffic parameters information. The format is different for different C-Type. C-Type = IntServ: See [RFC2210]; C-Type = Ethernet: See [RFC6003]; 3.2. FLOWSPEC Object The FLOWSPEC object (Class-Num = 9, Class-Type = TBD) has the same format as the Ethernet SENDER_TSPEC object. 3.3. Signaling Process The sender initiates PATH messages including one or more Bandwidth Profile TLVs with different availability value in the SENDER_TSPEC object. Each Bandwidth Profile TLV specifies the portion of bandwidth request with referred availability requirement. The receiving nodes check whether it can satisfy the bandwidth requirement by comparing each bandwidth requirement inside the SENDER_TSPEC objects with the unallocated link bandwidth resource with respective availability guarantee. o If all bandwidth requirements can be satisfied, it should allocate the bandwidth resource from each unallocated bandwidth portion for this LSP. o If at least one bandwidth requirement cannot be satisfied, it should generate PathErr messages. 4. Extension to Routing Protocol 4.1. Interface Switching Capacity Descriptor The Interface Switching Capacity Descriptor (ISCD) sub-TLV [RFC4203] has the following format: Long & Ye Expires August 18, 2013 [Page 6] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Cap | Encoding | AI | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Switching Capacity Information ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: TBD, 16 bits; Length: 16 bits; AI: ISCD Availability sub-TLV index, 8 bits This field is the index of availability sub-TLV for this ISCD sub-TLV. 4.2. ISCD Availability sub-TLV The 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Index | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Availability Information | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: TBD, 16 bits; Length: 16 bits; Index: 8 bits This field is the index of this availability sub-TLV, referred by the AI field of the ISCD sub-TLV. Availability Information: 32 bits This field is a 32-bit IEEE floating point number which describes the availability guarantee of the switching Long & Ye Expires August 18, 2013 [Page 7] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 capacity in the ISCD object which has the AI value equal to Index of this sub-TLV. The value must be less than 1. 5. Security Considerations This document does not introduce new security considerations to the existing RSVP-TE and OSPF signaling protocols. 6. IANA Considerations TBD 7. References 7.1. Normative References [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated Services", RFC2210, September 1997. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC3209, December 2001. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC3473, January 2003. [RFC4202] Kompella, K. and Rekhter, Y. (Editors), "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC4202, October 2005. [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC4203, October 2005. [RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC6003, October 2010. [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. Long & Ye Expires August 18, 2013 [Page 8] Internet-Draft RSVP-TE - Bandwidth Availability February 2013 7.2. Informative References [MCOS] Minei, I., Gan, D., Kompella, K., and X. Li, "Extensions for Differentiated Services-aware Traffic Engineered LSPs", Work in Progress, June 2006. 8. Acknowledgments Authors' Addresses Hao Long Huawei Technologies Co., Ltd. No.1899, Xiyuan Avenue, Hi-tech Western District Chengdu 611731, P.R.China Email: email@example.com Min Ye Huawei Technologies Co., Ltd. No.1899, Xiyuan Avenue, Hi-tech Western District Chengdu 611731, P.R.China Email: firstname.lastname@example.org Long & Ye Expires August 18, 2013 [Page 9]