INTERNET-DRAFT Mingui Zhang Intended Status: Proposed Standard Bin Wang Expires: June 22, 2014 Liang Xia Huawei December 19, 2013 Tagging Bridge Domains in VPLS draft-zhang-l2vpn-vpls-bd-tagging-00.txt Abstract When customers' Bridge Domains (BD) are interconnected using Virtual Private LAN Service, traffic of these BDs need be separated. This proposal suggests to use the service tag as a further de-multiplexor besides Pseudo-Wire to distinguish customers' BDs. Use cases are explored in this document. Status of this Memo This Internet-Draft is submitted to IETF 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License 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 Mingui Zhang, et al Expires June 22, 2014 [Page 1] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 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. Acronyms and Terminology . . . . . . . . . . . . . . . . . . . 3 2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Example Network . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. No Duplicated MAC Address . . . . . . . . . . . . . . . . . 4 4.2. BUM Traffic Scoped per BD . . . . . . . . . . . . . . . . . 4 4.3. Scalable Interconnection of L2 Sites . . . . . . . . . . . 5 4.4. Per S-tag Pruning and Dynamic VLAN Registration . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 Author's Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Mingui Zhang, et al Expires June 22, 2014 [Page 2] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 1. Introduction When VPLS is used to interconnect customers' layer2 networks, operators used to establish one VSI for each BD. When there is a large number of BDs need be interconnected, for example, in the environment of Data Center Networks, a lot of PWs must be set up [V- aware]. This kind of solution is not so scalable. This document suggests a service tag is used as an additional de- multiplexor of customers' BDs besides PW. By doing this, lots of BDs can share the same PW, which can greatly reduce the configuration overhead of PWs for operators and make the proposal be scalable. For example, if S-VLAN is used as the service tag, as many as 4094 BDs can be bundled in one PW. 2. Acronyms and Terminology 2.1. Acronyms MVRP: Multiple VLAN Registration Protocol BD: Bridge Domain/Broadcast Domain PW: Pseudo-Wire VSI: Virtual Switch Instance S-tag: Service tag S-VLAN: Service VLAN C-VLAN: Customer VLAN BUM: Broadcast, Unknown unicast and Multicast VLL: Virtual Leased Line 2.2. 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 RFC 2119 [RFC2119]. 3. Example Network Mingui Zhang, et al Expires June 22, 2014 [Page 3] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 +--------+ L2 +--------+ BD1 | PW L2 +--------+Stag=1 +---------------------- L2 +---+ +--------+ | | +----------------------+ | | +---+---+ | | | +--------+ |100|PKT| | +----+ BD11 | +---+---+ | L2 +--------+Stag=100+--------------+ L2 + | +--------+ | | L2 + | +---+---+ | | L2 + | +--------+ |200|PKT| | | L2 +--------+ BD12 | +---+---+ | | PW | |Stag=200+--------------+-------- | +--------+ | | | +---+---+ | | | +--------+ |300|PKT| | | L2 +--------+ BD13 | +---+---+ | | L2 +--------+Stag=300+--------------+ L2 + | +--------+ | L2 + | VSI| L2 + +----------------------+ L2 + PW L2 +-----------VLL--------------------------- Figure 3.1: Service tag as the de-multiplexor In Figure 3.1, an example is used to shown that service tag is used as an finer grained de-multiplexor along with PW for traffic segregation. Therefore, multiple BDs can be integrated into one VSI. 4. Use Cases 4.1. No Duplicated MAC Address For a specific Customer VLAN (C-VLAN) in different BDs, one MAC may be used by different hosts, which is illegal but it is the reality. If these BDs share the same PW, hosts in this C-VLAN will join in the same bridge domain. It therefore causes the MAC duplication issue. If operators use S-tag as the de-multiplexor, traffic of customers' BDs are separated. Above MAC duplication issue is avoided. 4.2. BUM Traffic Scoped per BD Suppose a customer has four sites in New York, Chicago, Atlanta and Dallas. BD1 = {New York, Chicago and Atlanta} while BD2 = {New York, Mingui Zhang, et al Expires June 22, 2014 [Page 4] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 Chicago and Dallas}. If one PW is set up to interconnect customers four sites. BUM traffic of Atlanta site will be poured to Dallas site, and vice versa. When the S-tag is used, the BUM traffic can be confined per BD. For above example, the operator need use two S-tags to distinguish the two BDs. In this way, BUM traffic of Atlanta site will be confined in BD1 and BUM traffic for Dallas site will be confined in BD2. This increases the efficiency of the bandwidth utilization of BUM traffic. 4.3. Scalable Interconnection of L2 Sites For the per PW bundling, when the connections (topologies) of sites in different BDs are different, operators used to set up different VSI to distinguish these BDs. The worst case is to set up one VSI per BD. This causes the scalability issue when there is a mass of BDs need be inter-connected. In this document, S-tag is used to distinguish BDs further, operators need not set up that many PWs. As shown in Figure 3.1, one PW is set up for each VSI and this VSI may be an integration of multiple BDs. 4.4. Per S-tag Pruning and Dynamic VLAN Registration Multiple VLAN Registration Protocol (MVRP) can be used for per- service-tag registration. For PEs connected by a PW, MVRP is used to register service tags configured on customers' BDs. Only when an S- tag is registered in both directions on this PW, BUM traffic with this S-tag can be transmitted on this PW. In this way, distributions trees of the BUM traffic is pruned. Since MVRP is used, operators need not reconfigure VLANs on their network devices when customers change their VLAN configuration. 5. Security Considerations This document raises no new security issues. For general security considerations, refer to [RFC4761] and [RFC4762]. 6. IANA Considerations This document requires no IANA actions. RFC Editor: please remove this section before publication. 7. References 7.1. Normative References Mingui Zhang, et al Expires June 22, 2014 [Page 5] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 [V-aware] D. Cai, S. Boutros, and et al, "VLAN Aware VPLS services", draft-cai-l2vpn-vpls-vlan-aware-bundling-00.txt, working in progress 7.2. Informative References [RFC4761] Kompella, K., Ed., and Y. Rekhter, Ed., "Virtual Private LAN Service (VPLS) Using BGP for Auto-Discovery and Signaling", RFC 4761, January 2007. [RFC4762] Lasserre, M., Ed., and V. Kompella, Ed., "Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling", RFC 4762, January 2007. Mingui Zhang, et al Expires June 22, 2014 [Page 6] INTERNET-DRAFT BD Interconnection Using VPLS December 19, 2013 Author's Addresses Mingui Zhang Huawei Technologies Email: zhangmingui@huawei.com Bin Wang Huawei Technologies Email: wb.wangbin@huawei.com Liang Xia Huawei Technologies Email: frank.xialiang@huawei.com Mingui Zhang, et al Expires June 22, 2014 [Page 7]