Network Working Group H. Long Internet Draft M.Ye Intended status: Standards Track Huawei Technologies Co., Ltd G. Mirsky Ericsson A Alessandro Telecom Italia S.p.A Expires: April 2014 October 18, 2013 RSVP-TE Signaling Extension for Links with Variable Discrete Bandwidth draft-long-ccamp-rsvp-te-bandwidth-availability-02.txt Abstract Packet switching network may contain 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 label switching path (LSP) in a Packet Switched Network (PSN) network which contains links with discretely variable bandwidth 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 April 18, 2014. Long, et al. Expires April 18, 2014 [Page 1] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 Copyright Notice Copyright (c) 2013 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 .................................................... 4 3. Extension to RSVP-TE Signaling............................... 4 3.1. SENDER_TSPEC Object..................................... 4 3.1.1. Bandwidth Profile TLV.............................. 5 3.2. FLOWSPEC Object......................................... 6 3.3. Signaling Process....................................... 6 4. Security Considerations...................................... 7 5. IANA Considerations ......................................... 7 5.1 RSVP Objects Class Types................................ 7 5.2 Ethernet Bandwidth Profile TLV ......................... 8 6. References .................................................. 9 6.1. Normative References.................................... 9 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 [RFC2119]. The following acronyms are used in this draft: RSVP-TE Resource Reservation Protocol-Traffic Engineering LSP Label Switched Path PSN Packet Switched Network Long, et al. Expires April 18, 2014 [Page 2] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 SNR Signal-to-noise Ratio TLV Type Length Value PE Provider Edge LSA Link State Advertisement 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. Some data communication technologies allow seamless change of maximum physical bandwidth through a set of known discrete values. 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 may lower the modulation level since demodulating lower modulation level need lower signal-to-noise ratio (SNR). This is called adaptive modulation technology [EN 302 217]. However, lower modulation level also means lower link bandwidth. When link bandwidth reduced because of modulation down-shifting, high priority traffic can be maintained, while lower priority traffic is dropped. Similarly the cooper links may change their link bandwidth due to external interference. The parameter, availability [G.827, F.1703, P.530], is often used to describe the link capacity during network planning. Assigning different availability classes to different types of service over such kind of links provides more efficient planning of link capacity. To set up a 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, 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 guarantee, multiple pairs may be required when signaling. To fulfill LSP setup by signaling in these scenarios, this document specifies a new availability sub-TLV as the sub-TLV of Ethernet bandwidth profiles [RFC6003]. Multiple bandwidth profiles with different availability can be carried in the SENDER_TSPEC object. Long, et al. Expires April 18, 2014 [Page 3] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 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, e.g., OSPF TE LSA message, by network nodes to get to know about the network topology, and calculate out an LSP route based on the network topology, and send the calculated LSP route to signaling to initiate a PATH/RESV message for setting up the LSP. In case that there is(are) link(s) with variable discrete bandwidth in a network, a requirement list should be specified for an LSP. Each pair in the list means that listed bandwidth with specified availability is required. The list could be inherited from the results of service planning for the LSP. When a PE node initiates a PATH/RESV signaling to set up an LSP, the PATH message SHOULD carry the requirement list as bandwidth request. Intermediate node(s) will allocate the bandwidth resource for each availability requirement from the remaining bandwidth with corresponding availability. An error message may be returned if any request cannot be satisfied. If there is a hop that cannot support the availability sub-TLV, the availability sub-TLV is ignored, and the requirement will be treated as the highest availability. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Granularity | MTU | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Long, et al. Expires April 18, 2014 [Page 4] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 Switching Granularity (SG): 16 bits See [RFC6003] section 4. MTU: 16bits See [RFC6003] section 4. 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. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CIR | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CBS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EIR | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EBS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: 0x02, 16 bits; Length: 16 bits; Profile: 8 bits This field is defined as a bit vector of binary flags. In RFC 6003, the following flags are defined: Flag 1 (bit 0): Coupling Flag (CF) Flag 2 (bit 1): Color Mode (CM) Long, et al. Expires April 18, 2014 [Page 5] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 A new flag is defined in this document: Flag 3 (bit 2): Availability Flag (AF) Index: 8 bits CIR (Committed Information Rate): 32 bits CBS (Committed Burst Size): 32 bits EIR (Excess Information Rate): 32 bits EBS (Excess Burst Size): 32 bits See [RFC6003] section 4.1. When the Flag 3 is set to value 1, there is an availability sub- TLV included in this Bandwidth Profile TLV. When the Flag 3 is set to value 0, there won't be an 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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. 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 source node initiates PATH messages including one or more Bandwidth Profile TLVs with different availability value in the Long, et al. Expires April 18, 2014 [Page 6] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 SENDER_TSPEC object. Each Bandwidth Profile TLV specifies the portion of bandwidth request with referred availability requirement. The destination node checks whether it can satisfy the bandwidth requirements by comparing each bandwidth requirement inside the SENDER_TSPEC objects with the remaining link sub-bandwidth resource with respective availability guarantee when received the PATH message. o If all bandwidth requirements can be satisfied, it should reserve the bandwidth resource from each remaining sub- bandwidth portion to set up this LSP. Optionally, the higher availability bandwidth can be allocated to lower availability request when the lower availability bandwidth cannot satisfy the request. o If at least one bandwidth requirement cannot be satisfied, it should generate PathErr message with the error code "Admission Control Error" and the error value "Requested Bandwidth Unavailable" (see [RFC2205]). 4. Security Considerations This document does not introduce new security considerations to the existing RSVP-TE signaling protocol. 5. IANA Considerations IANA maintains registries and sub-registries for RSVP-TE used by GMPLS. IANA is requested to make allocations from these registries as set out in the following sections. 5.1 RSVP Objects Class Types This document introduces two new Class Types for existing RSVP objects. IANA is requested to make allocations from the "Resource ReSerVation Protocol (RSVP) Parameters" registry using the "Class Names, Class Numbers, and Class Types" sub-registry. Class Number Class Name Reference ------------ ----------------------- --------- 9 FLOWSPEC [RFC2205] Class Type (C-Type): Long, et al. Expires April 18, 2014 [Page 7] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 6 Ethernet SENDER_TSPEC [RFC6003] Class Number Class Name Reference ------------ ----------------------- --------- 12 SENDER_TSPEC [RFC2205] Class Type (C-Type): 6 Ethernet SENDER_TSPEC [RFC6003] 5.2 Ethernet Bandwidth Profile TLV IANA maintains a registry of GMPLS parameters called ''Generalized Multi-Protocol Label Switching (GMPLS) Signaling Parameters''. IANA has created a new sub-registry called ''Ethernet Bandwidth Profiles'' to contain bit flags carried in the Ethernet Bandwidth Profile TLV of the Ethernet SENDER_TSPEC object. Bits are to be allocated by IETF Standards Action. Bits are numbered from bit 0 as the low order bit. A new bit flag is as follow: Bit Hex Description Reference --- ---- ------------------ ----------- 2 0x03 Availability Flag (AF) [This ID] Sub-TLV types for Ethernet Bandwidth Profiles are to be allocated by IETF Standard Action. Initial values are as follows: Type Length Format Description --- ---- ------------------ ----------- 0 - Reserved Reserved value TBD 4 see Section 3.1 Availability sub- TLV Long, et al. Expires April 18, 2014 [Page 8] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 6. References 6.1. Normative References [RFC2210] Wroclawski, J., ''The Use of RSVP with IETF Integrated Services'', RFC 2210, September 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. [RFC6003] Papadimitriou, D. ''Ethernet Traffic Parameters'', RFC 6003, 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. [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 6.2. 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. 7. Acknowledgments The authors would like to thank Khuzema Pithewan, Lou Berger, Yuji Tochio, Dieter Beller, and Autumn Liu for their comments on the document. Long, et al. Expires April 18, 2014 [Page 9] Internet-Draft RSVP-TE - Bandwidth Availability October 2013 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 Long, et al. Expires April 18, 2014 [Page 10]