MPLS Working Group G. Liu Internet-Draft ZTE Corporation Intended status: Informational Y. Weingarten Expires: April 26, 2012 Nokia Siemens Networks October 24, 2011 MPLS-TP protection for interconnected rings draft-liu-mpls-tp-interconnected-ring-protection-00 Abstract According to the ring protection Requirements in RFC 5654, Requirement 93 : When a network is constructed from interconnected rings, MPLS-TP MUST support recovery mechanisms that protect user data that traverses more than one ring. This includes the possibility of failure of the ring-interconnect nodes and links,so this document will describle all kinds of interconnected rings Scenario and a few possible solutions for recovery the failure of the ring-interconnect nodes and Links. . This document is a product of a joint Internet Task Force(IETF) / International Telecommunications Union Telecommunications Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and PWE3 architectures to support the capabilities and functionalities of a packet transport network 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. This document may not be modified, and derivative works of it may not be created, and it may not be published except as an Internet-Draft. 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 26, 2012. Liu & Weingarten Expires April 26, 2012 [Page 1] Internet-Draft MPLS-TP protection October 2011 Copyright Notice Copyright (c) 2011 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. Conventions used in this document . . . . . . . . . . . . . . 7 3. recovery mechanisms . . . . . . . . . . . . . . . . . . . . . 8 3.1. recovery mechanism for Dual-node interconnected-ring . . . 8 3.2. recovery mechanism for Single-node interconnected-ring . . 8 3.3. recovery mechanism for Chained interconnected-ring . . . . 8 3.4. recovery mechanism for Dual-node and Single-node mix interconnected-ring . . . . . . . . . . . . . . . . . . . 9 3.5. recovery mechanism for Dual-node and Chained mix interconnected-ring . . . . . . . . . . . . . . . . . . . 9 3.6. recovery mechanism for Single-node and Chained mix interconnected-ring . . . . . . . . . . . . . . . . . . . 9 3.7. recovery mechanism for Dual-node ,Single-node and Chained mix interconnected-ring . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.1. Normative References . . . . . . . . . . . . . . . . . . . 10 7.2. Informative References . . . . . . . . . . . . . . . . . . 10 7.3. URL References . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Liu & Weingarten Expires April 26, 2012 [Page 2] Internet-Draft MPLS-TP protection October 2011 1. Introduction This first version of the document will simply describle all kinds of interconnected rings scenario and a few protection solutions for the failure of the ring-interconnect nodes and links. For interconnected rings between two rings, there are mainly include three common interconnection scenario: Dual-node interconnection - when the interconnected rings are interconnected by two nodes from each ring (see Figure 1); Single-node interconnection - when the connection between the interconnected rings are through a single node (see Figure 2); Chain of rings - when a series of rings are connected through interconnection nodes that are part of both interconnected rings (see Figure 3) /LSR\******/LSR\******/LSR\xxxx/LSR\*****/LSR\******/LSR\ \_C_/ \_B_/ \_A_/ \_6_/ \_1_/ \_2_/ * * * * * Ring #1 * * Ring #2 * _*_ ___ _*_ _*_ ___ _*_ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\ \_D_/******\_E_/******\_F_/xxxx\_5_/*****\_4_/******\_3_/ *** physical link xxx interconnection link Figure 1 Liu & Weingarten Expires April 26, 2012 [Page 3] Internet-Draft MPLS-TP protection October 2011 ___ ___ ___ ___ /LSR\**********/LSR\ /LSR\*********/LSR\ \_C_/ \_B_/* *\_1_/ \_2_/ * * * * * * * * * * * * _*_ * ___ * _*_ /LSR\ Ring #1 /LSR\ Ring #2 /LSR\ \_D_/ *\_A_/* \_3_/ * * * * * * * * * * * * _*_ ___* *___ _*_ /LSR\ /LSR\ /LSR\ /LSR\ \_E_/***********\_F_/ \_5_/**********\_4_/ *** physical link Figure 2 ___ ___ ___ ___ ___ /LSR\******/LSR\******/LSR\*****/LSR\******/LSR\ \_C_/ \_B_/ \_A_/ \_1_/ \_2_/ * x * * Ring #1 x Ring #2 * _*_ ___ _x_ ___ _*_ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\ \_D_/******\_E_/******\_F_/*****\_4_/******\_3_/ *** physical link xxx shared link Liu & Weingarten Expires April 26, 2012 [Page 4] Internet-Draft MPLS-TP protection October 2011 Figure 3 when a traffic traveres more than two rings.there are mainly the following mix interconnection scenarios: Dual-node and single-node mix interconnection-when there not only exist two interconnected rings are interconnected by two nodes from each ring. but also there exist two interconnected rings are interconnected by single node( see figure 5); Dual-node and chained mix interconnection-when there exist two interconnnected rings are interconnected by two nodes from each ring. in addtion, there still exist two interconnnected rings are interconnected by a common chained link(see figure 4); single-node and chained mix interconnection-when there exist two interconnected rings are interconnected by single node, in addtion, there still exist two interconnected rings are interconnected by a common chained link(see figure 6); Dual-node, single-node and chained mix interconnection-when there exist all three interconnection scenrios in the network domain including Dual-node interconnnection, single-node interconnection and chained interconnnection( see figure 7); ___ /LSR\******/LSR\xx/LSR\****/LSR\ /LSR\**** /LSR\***/LSR\ \_C_/ \_B_/ \_A_/ \_6_/ \_1_/ \_2_/ \_H_/ * * * * * x * * x * * Ring 1 * * Ring 2 * .....*Ring 3 x Ring 4* _*_ *_ _*_ _*_ ___ ___ ___ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\*****/LSR\**/LSR\ \_D_/******\_E_/xx\_5_/*****\_4_/ \_k_/ \_L_/ \_M_/ *** physical link xxx interconnection link Figure 4 Liu & Weingarten Expires April 26, 2012 [Page 5] Internet-Draft MPLS-TP protection October 2011 ___ /LSR\******/LSR\xx/LSR\****/LSR\ /LSR\ /LSR\ \_C_/ \_B_/ \_A_/ \_6_/ \_1_/ *\_H_/ * * * * * * * * * * ___ * * * Ring 1 * * Ring 2 * .....*Ring 3/LSR\ Ring 4* _*_ *_ _*_ _*_ ___ * \_L_/* ___ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\* * /LSR\ \_D_/******\_E_/xx\_5_/*****\_4_/ \_k_/ \_M_/ *** physical link xxx interconnection link Figure 5 ___ /LSR\******/LSR\**/LSR\****/LSR\ /LSR\ /LSR\ \_C_/ \_B_/ \_A_/ \_6_/ \_1_/ *\_H_/ * x * * * * * * * ___ * * * Ring 1 x Ring 2 * .....*Ring 3/LSR\ Ring 4* _*_ _ _x_ _*_ ___ * \_L_/* ___ /LSR\ /LSR\ /LSR\ /LSR\ /LSR\* * /LSR\ \_D_/******\_E_/**\_5_/*****\_4_/ \_k_/ *\_M_/ *** physical link xxx interconnection link Figure 6 Liu & Weingarten Expires April 26, 2012 [Page 6] Internet-Draft MPLS-TP protection October 2011 ___ /LSR\******/LSR\xx/LSR\****/LSR\**** /LSR\ /LSR\ \_C_/ \_B_/ \_A_/ \_6_/ \_1_/ *\_H_/ * * * x x * * * x * ___ * * * Ring 1 * * Ring 2 xRing 5 xRing 3/LSR\ Ring 4* _*_ *_ _*_ _x_ ___ * \_L_/* ___ /LSR\ /LSR\ /LSR\ /LSR\****/LSR\* * /LSR\ \_D_/******\_E_/xx\_5_/*****\_4_/ \_k_/ *\_M_/ *** physical link xxx interconnection link Figure 7 For a multi-ring service, it will be accross more than one ring just like above seven scenrios. if a failur happens on a multi-ring path, quickly recovery is necessary requirement for MPLS-TP network, so there are describles for recoverying the failure in the multi-ring interconnection sencrios in the following sections . 2. 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. OAM: Operations, Administration, Maintenance LSP: Label Switched Path. TLV: Type Length Value P2MP:Point to Multi-Point P2P:Point to Point PSC:Protection Switching Coordination SD:Signal Degrade Liu & Weingarten Expires April 26, 2012 [Page 7] Internet-Draft MPLS-TP protection October 2011 SF:Signal Fail RDI:Remote Defect Indication SPME:Sub-Path Maintenance Entity MPLS-TP:Multi-Protocol Label Switching Transport Profile ME: Maintenance Entity MEP:MEG End Point ACH: Associated Channel Header CC-V: Contunuity Check-Verification; 3. recovery mechanisms This section will describle recovery mechanisms that protect multi- ring traffics,which traver more than one ring in case of failure for all kinds of interconnection-ring scenrios; 3.1. recovery mechanism for Dual-node interconnected-ring Under the interconnected-ring scenrios just as figure 1,multi-ring traffics will be transported by interconnection link(LSR C-LSR 6). when a failure happened on the interconnection link, if a segment protection path has been set up for the interconnection link , maybe apply 1:1 linear protection to protect the interconnection link faiure for interconnected-ring; or else, it maybe need end to end multi-ring path switch to protect the interconnection link failure. . 3.2. recovery mechanism for Single-node interconnected-ring for the single-node interconnected-ring scenrio, As the interconnection node (LSR-A in Figure 2) is a single-point of failure , such an interconnection scheme should be avoided. . 3.3. recovery mechanism for Chained interconnected-ring For the chained interconnected-ring scenrio, if the interconnection nodes(LSR-A and LSR-F) or the shared link(LSR-A-LSR-F) have failures, single ring protection solution can't recovery the failure, so the affected multi-ring traffics maybe be protected by end to end protection path; . Liu & Weingarten Expires April 26, 2012 [Page 8] Internet-Draft MPLS-TP protection October 2011 3.4. recovery mechanism for Dual-node and Single-node mix interconnected-ring for the mix interconnected-ring scenrios, each interconnection nodes or shared interconnection link will be protected by setting up segment protection path seperately. in addition, it may still use end to end multi-ring protection path to protect multiple interconnection nodes or shared interconnection link failure. . 3.5. recovery mechanism for Dual-node and Chained mix interconnected- ring . for the mix interconnected-ring scenrios, each interconnection nodes or shared interconnection link will be protected by setting up segment protection path seperately. in addition, it may still use end to end multi-ring protection path to protect multiple interconnection nodes or shared interconnection link failure. 3.6. recovery mechanism for Single-node and Chained mix interconnected- ring for the mix interconnected-ring scenrios, each interconnection nodes or shared interconnection link will be protected by setting up segment protection path seperately. in addition, it may still use end to end multi-ring protection path to protect multiple interconnection nodes or shared interconnection link failure. 3.7. recovery mechanism for Dual-node ,Single-node and Chained mix interconnected-ring for the mix interconnected-ring scenrios, each interconnection nodes or shared interconnection link will be protected by setting up segment protection path seperately. in addition, it may still use end to end multi-ring protection path to protect multiple interconnection nodes or shared interconnection link failure. 4. Security Considerations TBD 5. IANA Considerations TBD. Liu & Weingarten Expires April 26, 2012 [Page 9] Internet-Draft MPLS-TP protection October 2011 6. Acknowledgments TBD . 7. References 7.1. Normative References [RFC 5654] IETF, "IETF RFC5654(MPLS-TP requirement)", September 2009. [RFC 5921] IETF, "IETF RFC5654(MPLS-TP framework)", July 2010. [RFC 6372] N. Sprecher, A. Farrel, "Multiprotocol Label Switching Transport Profile Survivability Framework", September 2011. 7.2. Informative References [MPLS-TP Linear protection] S. Bryant, N. Sprecher, H. van Helvoort,A. Fulignoli Y. Weingarten, "MPLS transport profile Linear Protection", July 2010. [MPLS-TP Ring Protection] Y. Weingarten, "Multiprotocol Label Switching Transport Profile Ring Protection", Sep 2011. 7.3. URL References [MPLS-TP-22] IETF - ITU-T Joint Working Team, "", 2008, . Liu & Weingarten Expires April 26, 2012 [Page 10] Internet-Draft MPLS-TP protection October 2011 Authors' Addresses Liu guoman ZTE Corporation No.50, Ruanjian Road, Yuhuatai District Nanjing 210012 P.R.China Phone: +86 025 52871606 Email: liu.guoman@zte.com.cn Yaacov Weingarten Nokia Siemens Networks 3 Hanagar St. Neve Ne'eman B Hod Hasharon 45241 Israel Phone: +972-9-775 1827 Email: yaacov.weingarten@nsn.com Liu & Weingarten Expires April 26, 2012 [Page 11]