SFC WG C. Wu Internet-Draft Zhejiang University Intended status: Standards Track C. Wang Expires: June 6, 2015 W. Meng ZTE Corporation B. Khasnabish ZTE TX, Inc. December 3, 2014 Multi-Layer OAM for Service function Chaining draft-wang-sfc-multi-layer-oam-01 Abstract Since there are different notions of service chain, such as fully abstract notion named SFC, half-fully abstraction notion named SFP and fully specific notion named RSP, and there are different components defined in SFC architecture, it seems reasonable to define differentiated OAM for these different service chains. This document tries to discuss the multi-layer OAM requirements in SFC domain and provides a multi-layer OAM solution for different service chains. 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). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on June 6, 2015. 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 Wu, et al. Expires June 6, 2015 [Page 1] Internet-Draft Multi-Layer OAM for SFC December 2014 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. Convention and Terminology . . . . . . . . . . . . . . . . . . 4 3. Requirement . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Multi-layer SFC OAM architecture . . . . . . . . . . . . . . . 7 5. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 Wu, et al. Expires June 6, 2015 [Page 2] Internet-Draft Multi-Layer OAM for SFC December 2014 1. Introduction Since there are different notions of service chain, such as fully abstract notion named SFC, half-fully abstraction notion named SFP and fully specific notion named RSP, and there are different components defined in SFC architecture, it seems reasonable to define differentiated OAM for these different service chains. This document tries to discuss the multi-layer OAM requirements in SFC domain and provides a multi-layer OAM solution for different service chains. Wu, et al. Expires June 6, 2015 [Page 3] Internet-Draft Multi-Layer OAM for SFC December 2014 2. Convention and Terminology 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 [RFC2119]. The terms are all defined in [I-D.ietf-sfc-architecture]. Wu, et al. Expires June 6, 2015 [Page 4] Internet-Draft Multi-Layer OAM for SFC December 2014 3. Requirement In fact, besides the link layer OAM, network layer OAM, SFC service layer OAM is requisite in SFC Domain, which may be typically illustrated in Figure 1. +-----------+ +---+ +---+ +---+ +---+ +---+ |Classifier |---|SF1|---|SF2|---|SF3|---|SF4|---|SF5| +-----------+ +---+ +---+ +---+ +---+ +---+ |------------SFC Service layer OAM------------| Figure 1: typical SFC service layer OAM Currently, according to the latest SFC architecture, we know that there are several components defined in the SFC architecture, such as SN, SFF, SF,etc, and the relationship between them like this: serveral SFs may share the same SFF, and furthermore, serveral SFFs may share the same SN(e.g, different SFFs residented in one service node belong to different VPNs). As a result of that, multiple RSPs, such as RSP1(SF1--SF3--SF5) and RSP2(SF2--SF4--SF6) in Figure 2, may not share the same transmitting path, but they may share the same SFFs path. +---+ +---+ +---+ +---+ +---+ +---+ |SF1| |SF2| |SF3| |SF4| |SF5| |SF6| +---+ +---+ +---+ +---+ +---+ +---+ \ / \ / \ / +-----------+ +----+ +----+ +----+ |Classifier |---|SFF1|-----------|SFF2|-----------|SFF3| +-----------+ +----+ +----+ +----+ Figure 2: different RSPs share the same SFFs path And also, multiple SFPs, such as SFP1(SFF1--SFF3--SFF5)(e.g, VPN1) and SFP2(SFF2--SFF4--SFF6)(e.g, VPN2) in Figure 3, may not share the same SFFs, but they may share the same SNs path. Wu, et al. Expires June 6, 2015 [Page 5] Internet-Draft Multi-Layer OAM for SFC December 2014 +----+ +----+ +----+ +----+ +----+ +----+ |SFF1| |SFF2| |SFF3| |SFF4| |SFF5| |SFF6| +----+ +----+ +----+ +----+ +----+ +----+ \ / \ / \ / +-----------+ +----+ +----+ +----+ |Classifier |---|SN1 |------------|SN2 |-------------|SN3 | +-----------+ +----+ +----+ +----+ Figure 3: different SFPs share the same SNs path As for users who want to diagnose, troubleshoot a set of RSPs which transmit the same SFFs, or a set of SFPs which transmit the same SNs, there is an aggregative method which can aggregate a set of RSPs or a set of SFPs into one, then, users only need to diagnose, troubleshoot the aggregative one, rather than the separated one by one. And also, if users are willing to diagnose and troubleshoot one by one, once the connectivity between different SFs is not OK, users can detect the connectivity between different SFFs where the SFs resident instead to narrow the failure coverage. In other words, if the connectivity between the detected SFFs is not OK, then the connectivity problem is located. if the connectivity betwwen the detected SFFs is OK, then the connectivity problem should be between the detected SFs and the detected SFFs, which can help to improve the efficiency of target location remarkably. Obviously, they can be diagnosed, troubleshooted one by one or aggregatively according to preferance. As follow, this document tries to provide an architecture and a solution for differentiated layer OAM for this requirement. Wu, et al. Expires June 6, 2015 [Page 6] Internet-Draft Multi-Layer OAM for SFC December 2014 4. Multi-layer SFC OAM architecture Figure 4 is a possible architecture for multi-layer SFC OAM. In this figure, it tries to figure out three possible layers. The layer 1 is the most aggregative layer for service chain. It stretches the path which SNs go through according to the sets of RSPs or SFPs or SFCs. The layer 2 is the medium aggregative layer for service chain. It outlines the path which SFFs go though according to the sets of RSPs or SFPs or SFCs. The layer 3 is the specific path for service chain. It is exactly the path which SFs go though according to the sets of RSPs or SFPs or SFCs. +---+ +---+ +----+ +----+ +-----+ +-----+ +------+ +------+ |SF1|..|SFn| |SF1'|..|SFn'| |SF1''|..|SFn''| |SF1'''|..|SFn'''| +---+ +---+ +----+ +----+ +-----+ +-----+ +------+ +------+ \ / \ / | \ / \ / | +----+ +----+ | +-----+ +-----+ | |SFF1| ... |SFFn| | |SFF1'| ... |SFFn'| | +----+ +----+ | +-----+ +-----+ | \ / | | \ / | | +-----------+ +-------+ | | +-------+ | | |Classifier |------| SN1 |---|------|------------------| SNn | | | +-----------+ +-------+ | | +-------+ | | | | | | | | |------|------|-Layer 1---------------| | | | | | | |------|--------Layer 2-----------------| | | | |--------------Layer 3-----------------| | | Figure 4: a possible architecture for multi-layer SFC OAM Wu, et al. Expires June 6, 2015 [Page 7] Internet-Draft Multi-Layer OAM for SFC December 2014 5. Solution If anyone is interested in this requirement, I will update the solution in the next version. Wu, et al. Expires June 6, 2015 [Page 8] Internet-Draft Multi-Layer OAM for SFC December 2014 6. Security Considerations It will be considered in a future revision. Wu, et al. Expires June 6, 2015 [Page 9] Internet-Draft Multi-Layer OAM for SFC December 2014 7. IANA Considerations It will be considered in a future revision. Wu, et al. Expires June 6, 2015 [Page 10] Internet-Draft Multi-Layer OAM for SFC December 2014 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 8.2. Informative References [I-D.boucadair-sfc-requirements] Boucadair, M., Jacquenet, C., Jiang, Y., Parker, R., Pignataro, C., and K. Kengo, "Requirements for Service Function Chaining (SFC)", draft-boucadair-sfc-requirements-05 (work in progress), July 2014. [I-D.ietf-sfc-architecture] Halpern, J. and C. Pignataro, "Service Function Chaining (SFC) Architecture", draft-ietf-sfc-architecture-02 (work in progress), September 2014. [I-D.ietf-sfc-problem-statement] Quinn, P. and T. Nadeau, "Service Function Chaining Problem Statement", draft-ietf-sfc-problem-statement-10 (work in progress), August 2014. [I-D.krishnan-sfc-oam-req-framework] Krishnan, R., Ghanwani, A., Gutierrez, P., Lopez, D., Halpern, J., Kini, S., and A. Reid, "SFC OAM Requirements and Framework", draft-krishnan-sfc-oam-req-framework-00 (work in progress), July 2014. Wu, et al. Expires June 6, 2015 [Page 11] Internet-Draft Multi-Layer OAM for SFC December 2014 Authors' Addresses Wu Chunming Zhejiang University No.38 Zheda Road, Xihu District Hangzhou China Email: wuchunming@zju.edu.cn Cui Wang ZTE Corporation No.50 Software Avenue, Yuhuatai District Nanjing China Email: wang.cui1@zte.com.cn Wei Meng ZTE Corporation No.50 Software Avenue, Yuhuatai District Nanjing China Email: meng.wei2@zte.com.cn,vally.meng@gmail.com Bhumip Khasnabish ZTE TX, Inc. 55 Madison Avenue, Suite 160 Morristown, New Jersey 07960 USA Email: bhumip.khasnabish@ztetx.com Wu, et al. Expires June 6, 2015 [Page 12]