Network Working Group Q. Wang Internet-Draft X. Fu Intended status: Standards Track G. Liu Expires: April 20, 2012 ZTE Corporation Oct 18, 2011 Requirements for GMPLS Routing for ASON draft-wang-ccamp-rfc4258bis-00 Abstract The Generalized Multi-Protocol Label Switching (GMPLS) suite of protocols has been defined to control different switching technologies as well as different applications. These include support for requesting Time Division Multiplexing (TDM) connections including Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) and Optical Transport Networks (OTNs). Along with the development of technology, some new routing requirements which are addressed in G.7715.1 emerge. This document concentrates on the new routing requirements addressed in G.7715.1 and placed on the GMPLS suite of protocols in order to support the capabilities and functionalities of an Automatically Switched Optical Network (ASON) as defined by the ITU-T. 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 April 20, 2012. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. Wang, et al. Expires April 20, 2012 [Page 1] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 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 1.1. Conventions Used in This Document . . . . . . . . . . . . . 3 2. New Routing Requirements . . . . . . . . . . . . . . . . . . . 3 3. New Routing Attributes . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. Normative References . . . . . . . . . . . . . . . . . . . 6 5.2. Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Wang, et al. Expires April 20, 2012 [Page 2] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 1. Introduction The Generalized Multi-Protocol Label Switching (GMPLS) suite of protocols provides, among other capabilities, support for controlling different switching technologies. These include support for requesting TDM connections utilizing SONET/SDH (see [T1.105] and [G.707], respectively) as well as Optical Transport Networks (OTNs, see [G.709]). However, there are certain capabilities that are needed to support the ITU-T G.8080 control plane architecture for an Automatically Switched Optical Network (ASON). Therefore, it is desirable to understand the corresponding requirements for the GMPLS protocol suite. The ASON control plane architecture is defined in [G.8080]; ASON routing requirements are identified in [G.7715] and in [G.7715.1] for ASON link state protocols. These Recommendations apply to all [G.805] layer networks (e.g., SDH and OTN), and provide protocol-neutral functional requirements and architecture. RFC4258 focuses on the routing requirements for the GMPLS suite of protocols to support the capabilities and functionality of ASON control planes. Along with the development of technology, some new routing technology emerged in G.7715.1, whereas not in RFC4258. So this document mainly focuses on these new routing requirements which are not addressed in RFC4258. This document does not address GMPLS applicability or GMPLS capabilities. Any protocol (in particular, routing) applicability, design, or suggested extensions are strictly outside the scope of this document. 1.1. 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 [RFC2119]. Although [RFC2119] describes interpretations of these key words in terms of protocol specifications and implementations, they are used in this document to describe design requirements for protocol extensions. 2. New Routing Requirements Routing for transport networks is performed on a per-layer basis, where the routing paradigms MAY differ among layers and within a layer. Not all equipment supports the same set of transport layers or the same degree of connection flexibility at any given layer. A difference of the definition of layer exists between G.800 and G.8080 and each SHOULD be treated as a separate layer. While RFC4258 addresses the routing Wang, et al. Expires April 20, 2012 [Page 3] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 requirement that signal types can also be advertised, different attributes (e.g., link weight, resource class, SRG) SHOULD also be able to be advertised per signal type. While RFC4258 describes in section 5.1 how to identify links that go between "technology regions" (cf. RFC4206), it doesn't handle the identification of layers that exist within regions. For example, when refer to TDM technology region, multiple layers (e.g., VC3 vs VC4 within the TDM/SDH) MAY exist within one technology region. In order to explicitly identify these layers, Switching/termination capabilities of a link end SHOULD be introduced to address this. Multiple adaption methods MAY exist between layers (e.g., X.86 vs GFP, 802.3 vs Ethernet V2), so there SHOULD be a mechanism introduced to identify the specific client adaption methods supported on a link end. This is a new routing requirement that is not addressed by RFC4258. 3. New Routing Attributes The new routing requirements and attributes described in section 3 mainly pertain to link attributes, so in this draft, this section mainly focuses on the updates to the routing requirements of link attributes on the basis of RFC4258. That is to say, except the routing requirements of link attributes described in this section, the other routing requirements are in accordance with RFC4258. So before you read this draft, make sure you are familiar with RFC4258. The section 4.1.4 of RFC4258 describes the link attributes of ASON routing architecture and requirements. Link attributes include local SNPP link ID, remote SNPP link ID and layer specific characteristic. This document has nothing to do with local SNPP link ID and remote SNPP link ID, while new routing requirements are only added to the layer specific characteristics. Table 3 of RFC4258 lists the link characteristics which is also included followed. New routing requirements described here that are related to the corresponding link characteristics are Signal Type, Local Adaptation Support and Termination/Switching Identification. Wang, et al. Expires April 20, 2012 [Page 4] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 Link Characteristics Capability Usage ----------------------- ---------- --------- Signal Type REQUIRED OPTIONAL Link Weight REQUIRED OPTIONAL Resource Class REQUIRED OPTIONAL Local Connection Types REQUIRED OPTIONAL Link Capacity REQUIRED OPTIONAL Link Availability OPTIONAL OPTIONAL Diversity Support OPTIONAL OPTIONAL Local Adaptation Support OPTIONAL OPTIONAL Termination/Switching Identification OPTIONAL OPTIONAL Figure 1: Format of the sub-TLV - Signal Type: This identifies the characteristic information of the layer network. Attributes of one signal SHALL be able to be advertised following the relational signal type. The signal attributes indicated here is a new routing requirement to RFC4258. - Link Weight: This is the metric indicating the relative desirability of a particular link over another, e.g., during path computation. - Resource Class: This corresponds to the set of administrative groups assigned by the operator to this link. A link MAY belong to zero, one, or more administrative groups. - Local Connection Types: This attribute identifies whether the local SNP represents a Termination Connection Point (CP), a Connection Point (CP), or can be flexibly configured as a TCP. - Link Capacity: This provides the sum of the available and potential bandwidth capacity for a particular network transport layer. Other capacity measures MAY be further considered. - Link Availability: This represents the survivability capability such as the protection type associated with the link. - Diversity Support: This represents diversity information such as the SRLG information associated with the link. - Local Adaptation Support: This indicates the set of client layer adaptations supported by the TCP associated with the local SNPP. This is applicable only when the local SNP represents a TCP or can be flexibly configured as a TCP. A new requirement is that a mechanism SHOULD be introduced to identify the specific client adaption methods supported on a link end when multiple adaption methods exist between Wang, et al. Expires April 20, 2012 [Page 5] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 layers. - Termination/Switching Identification: Capability introduced to handle the identification of layers that exist within regions (e.g., VC3 vs VC4 within the TDM/SDH). This is a new routing requirement to RFC4258. 4. Security Considerations TBD 5. References 5.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5787] Papadimitriou, D., "OSPFv2 Routing Protocols Extensions for Automatically Switched Optical Network (ASON) Routing", RFC 5787, March 2010. 5.2. Informative References [G.709] ITU-T Recommendation G.709, "Interfaces for the Optical Transport Network (OTN)", December 2009. [G.7715.1] "ASON Routing Architecture and Requirements for Link State Protocols", ITU-T Draft Rec. G.7715.1/Y.1706.1 , December 2007. [RFC4258] Brungard, D., "Requirements for Generalized Multi-Protocol Label Switching (GMPLS) Routing for the Automatically Switched Optical Network (ASON)", RFC 4258, November 2005. Wang, et al. Expires April 20, 2012 [Page 6] Internet-Draft Requirements for GMPLS Routing for ASON Oct 2011 Authors' Addresses Qilei Wang ZTE Corporation No.68 ZiJingHua Road,Yuhuatai District Nanjing 210012 P.R.China Email: wang.qilei@zte.com.cn URI: http://wwwen.zte.com.cn/ Xihua Fu ZTE Corporation West District,ZTE Plaza,No.10,Tangyan South Road,Gaoxin District Xi An 710065 P.R.China Phone: +8613798412242 Email: fu.xihua@zte.com.cn URI: http://wwwen.zte.com.cn/ Guoman Liu ZTE Corporation No.68 ZiJingHua Road,Yuhuatai District Nanjing 210012 P.R.China Email: liu.guoman@zte.com.cn URI: http://wwwen.zte.com.cn/ Wang, et al. Expires April 20, 2012 [Page 7]