Network Working Group H. Long, M. Ye Internet Draft Huawei Technologies Co., Ltd Intended status: Standards Track G. Mirsky Ericsson A. Alessandro Telecom Italia S.p.A H. Shah Ciena Expires: April 2015 October 8, 2014 RSVP-TE Signaling Extension for Links with Variable Discrete Bandwidth draft-ietf-ccamp-rsvp-te-bandwidth-availability-00.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 Extended Ethernet Bandwidth Profile TLV and an OPTIONAL Availability sub_TLV 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 Long, et al. Expires April 8, 2015 [Page 1] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 This Internet-Draft will expire on April 8, 2014. Copyright Notice Copyright (c) 2014 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............................... 5 3.1.1. Extended Ethernet Bandwidth Profile TLV............ 5 3.1.2. Availability sub-TLV............................... 6 3.2. FLOWSPEC Object......................................... 6 3.3. Signaling Process....................................... 6 4. Security Considerations...................................... 7 5. IANA Considerations ......................................... 7 5.1 Ethernet Sender TSpec TLVs ............................. 7 5.2 Extended Ethernet Bandwidth Profile TLV ................ 8 6. References .................................................. 8 6.1. Normative References.................................... 8 6.2. Informative References.................................. 9 7. Acknowledgments ............................................. 9 Appendix A ..................................................... 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 Long, et al. Expires April 8, 2015 [Page 2] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 PSN Packet Switched Network 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. A more detailed example on the bandwidth availability can be found in Appendix A. 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 guarantee, multiple pairs MAY be required when signaling. If the availability requirement is not specified in the signaling message, the bandwidth will be reserved as the highest availability. Long, et al. Expires April 8, 2015 [Page 3] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 For example, the bandwidth with 99.999% availability of a link is 100Mbps; the bandwidth with 99.99% availability is 200Mbps. When a video application requests for 120Mbps without availability requirement, the system will compare 120Mbps with 100Mbps, therefore cannot set up the LSP path. But in fact, video application doesn't need 99.999% availability, 99.99% availability is enough. In this case, the LSP could be set up if availability is specified in the signaling message. To fulfill LSP setup by signaling in these scenarios, this document specifies an Extended Ethernet Bandwidth Profile and an Availability sub-TLV. The Availability sub-TLV can be applicable to any kind of physical links with variable discrete bandwidth, such as microwave or DSL. Multiple Extended Ethernet Bandwidth Profiles with different availability can be carried in the Ethernet SENDER_TSPEC object. 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. A node which has link(s) with variable discrete 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 PE node(s). The routing extension for availability can be found in [ARTE]. 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. Long, et al. Expires April 8, 2015 [Page 4] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 3. Extension to RSVP-TE Signaling The initial idea is to define an Availability sub_TLV under Ethernet Bandwidth Profile TLV [RFC6003]. However the Ethernet Bandwidth Profile TLV doesn't have the ability to carry a sub_TLV according to RFC6003. Therefore, an Extend Ethernet Bandwidth Profile TLV is defined in this document to avoid the backward compatibility issue. The Extended Ethernet Bandwidth Profile TLV includes Ethernet BW TLV and has variable length. It MAY include Availability sub-TLV which is also defined in this document. 3.1.1. Extended Ethernet Bandwidth Profile TLV The Extended Ethernet Bandwidth Profile TLV is included in the Ethernet SENDER_TSPEC, and MAY be included for more than one time. The Extended Ethernet 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Pro|A| | Index | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CIR | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CBS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EIR | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EBS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub_TLV(OPTIONAL) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: A new ''AF'' filed in Extended Ethernet Bandwidth Profile TLV The difference between the Extended Ethernet Bandwidth Profile TLV and Ethernet Bandwidth Profile TLV is that a new AF field to indicate the sub_TLV is defined in the Extended Ethernet Bandwidth Profile TLV. The rest definitions are the same. A new filed is defined in this document: AF filed (bit 2): Availability Field (AF) Long, et al. Expires April 8, 2015 [Page 5] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 If the AF filed is set to 1, Availability sub-TLV MUST be included in the Extended Ethernet Bandwidth Profile TLV. If the AF field is set to value 0, then an Availability sub-TLV SHOULD NOT be included. 3.1.2. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Availability sub-TLV Type (2 octets): TBD Length (2 octets): 4 Availability (4 octets): a 32-bit floating number describes the decimal value of availability requirement for this bandwidth request. The value MUST be less than 1. As the Extended Ethernet Bandwidth Profile TLV can be carried for one or more times in the Ethernet SENDER_TSPEC object, the Availability sub-TLV can also be present for one or more times. 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 Extended Bandwidth Profile TLVs with different availability value in the SENDER_TSPEC object. Each Extended Bandwidth Profile TLV specifies the portion of bandwidth request with referred availability requirement. The intermediate and destination nodes checks whether they can satisfy the bandwidth requirements by comparing each bandwidth requirement inside the SENDER_TSPEC objects with the remaining link Long, et al. Expires April 8, 2015 [Page 6] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 sub-bandwidth resource with respective availability guarantee when received the PATH message. o If all 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 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]). If two LSPs request for the bandwidth with the same availability requirement, a way to resolve the contention is comparing the node ID, the node with the higher node ID will win the contention. More details can be found in [RFC3473]. If a node does not support the Extended Bandwidth Profile TLV and Availability sub-TLV, it SHOULD generate PathErr message with the error code "Extended Class-Type Error" and the error value "Class- Type mismatch" (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 Ethernet Sender TSpec TLVs 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 Sender TSpec TLVs / Ethernet Flowspec TLVs'' to contain the TLV type values for TLVs carried in the Ethernet SENDER_TSPEC object. A new value is as follow: Long, et al. Expires April 8, 2015 [Page 7] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 Type Description Reference ----- ----------------------------------- --------- TBD Extended Ethernet Bandwidth Profile [This ID] 5.2 Extended Ethernet Bandwidth Profile TLV IANA has created a new sub-registry called ''Extended Ethernet Bandwidth Profiles'' to contain bit flags carried in the Extended 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 field is as follow: Bit Hex Description Reference --- ---- ------------------ ----------- 0 0x01 Coupling Flag (CF) [RFC6003] 1 0x02 Color Mode (CM) [RFC6003] 2 0x03 Availability Field (AF) [This ID] Sub-TLV types for Extended Ethernet Bandwidth Profiles are to be allocated by IETF Standard Action. Initial values are as follows: Type Length Format Description --- ---- ------------------ ----------- 0 - Reserved Reserved value 0x01 4 see Section 3.1.2 Availability sub-TLV 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. Long, et al. Expires April 8, 2015 [Page 8] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 [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 [ARTE] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., ''OSPF Routing Extension for Links with Variable Discrete Bandwidth'', Work in Progress, February, 2014 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. Appendix A Presuming that a link has three discrete bandwidth levels: The link bandwidth under modulation level 1, e.g., QPSK, is 100Mbps; The link bandwidth under modulation level 2, e.g., 16QAM, is 200Mbps; Long, et al. Expires April 8, 2015 [Page 9] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 The link bandwidth under modulation level 3, e.g., 256QAM, is 400Mbps. In sunny day, the modulation level 3 can be used to achieve 400Mbps link bandwidth. A light rain with X mm/h rate triggers the system to change the modulation level from level 3 to level 2, with bandwidth changing from 400Mbps to 200Mbps. The probability of X mm/h rain in the local area is 52 minutes in a year. Then the dropped 200Mbps bandwidth has 99.99% availability. A heavy rain with Y(Y>X) mm/h rate triggers the system to change the modulation level from level 2 to level 1, with bandwidth changing from 200Mbps to 100Mbps. The probability of Y mm/h rain in the local area is 26 minutes in a year. Then the dropped 100Mbps bandwidth has 99.995% availability. For the 100M bandwidth of the modulation level 1, only the extreme weather condition can cause the whole system unavailable, which only happens for 5 minutes in a year. So the 100Mbps bandwidth of the modulation level 1 owns the availability of 99.999%. In a word, the maximum bandwidth is 400Mbps. According to the weather condition, the sub-bandwidth and its availability are shown as follows: Sub-bandwidth(Mbps) Availability ------------------ ------------ 200 99.99% 100 99.995% 100 99.999% Long, et al. Expires April 8, 2015 [Page 10] Internet-Draft RSVP-TE - Bandwidth Availability October 2014 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 (editor) Huawei Technologies Co., Ltd. No.1899, Xiyuan Avenue, Hi-tech Western District Chengdu 611731, P.R.China Email: amy.yemin@huawei.com Greg Mirsky (editor) 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 April 8, 2015 [Page 11]