INTERNET-DRAFT Mingui Zhang Intended Status: Proposed Standard Huafeng Wen Expires: November 3, 2013 Huawei May 2, 2013 STP Application of ICCP draft-zhang-iccp-stp-03.txt Abstract Inter-Chassis Communication Protocol (ICCP) supports the inter- chassis redundancy mechanism which achieves high network availability. In this document, the PEs in a Redundant Group (RG) running ICCP are used to offer multi-homed connectivity to Spanning Tree Protocol (STP) networks. The ICCP TLVs for the STP application are defined, therefore PEs from the RG can make use of these TLVs to synchronize the state and configuration data. 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 Mingui Zhang Expires November 3, 2013 [Page 1] INTERNET-DRAFT STP Application of ICCP May 2, 2013 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 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 2. The Use Case Scenario . . . . . . . . . . . . . . . . . . . . . 3 2.1. Virtual Root Bridge . . . . . . . . . . . . . . . . . . . . 4 3. Spanning Tree Protocol Application TLVs . . . . . . . . . . . . 4 3.1. STP Connect TLV . . . . . . . . . . . . . . . . . . . . . . 4 3.2. STP Disconnect TLV . . . . . . . . . . . . . . . . . . . . 5 3.2.1. STP Disconnect Cause TLV . . . . . . . . . . . . . . . 6 3.3. STP Config TLVs . . . . . . . . . . . . . . . . . . . . . . 7 3.3.1. STP System Config . . . . . . . . . . . . . . . . . . . 7 3.3.2. STP Topology Changed Instances . . . . . . . . . . . . 8 3.3.3. STP CIST Root Time . . . . . . . . . . . . . . . . . . 8 3.3.4. STP MSTI Root Time . . . . . . . . . . . . . . . . . . 9 3.3.5. STP Region Name . . . . . . . . . . . . . . . . . . . . 10 3.3.6. STP Revision Level . . . . . . . . . . . . . . . . . . 11 3.3.7. STP Instance Priority . . . . . . . . . . . . . . . . . 11 3.3.8. STP Configuration Digest . . . . . . . . . . . . . . . 12 3.4. STP Synchronization Request TLV . . . . . . . . . . . . . . 13 3.5. STP Synchronization Data TLV . . . . . . . . . . . . . . . 14 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 15 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 15 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.1. Normative References . . . . . . . . . . . . . . . . . . . 15 6.2. Informative References . . . . . . . . . . . . . . . . . . 15 Author's Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Mingui Zhang Expires November 3, 2013 [Page 2] INTERNET-DRAFT STP Application of ICCP May 2, 2013 1. Introduction Inter-Chassis Communication Protocol (ICCP) specifies a multi-chassis redundant mechanism, which enables PEs located in multi-chassis to act as a single Redundant Group (RG). When a bridge network running Spanning Tree Protocol (STP) is connected to an RG, the RG members can pretend to be a single root bridge to participate the operations of STP. STP relevant information need be exchanged and synchronized among the RG members. ICCP TLVs for the Spanning Tree Protocol application are specified for this purpose in 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 RFC 2119 [RFC2119]. 1.2. Terminology STP: Spanning Tree Protocol MSTP: Multiple Spanning Tree Protocol DSLAM: Digital Subscriber Line Access Multiplexer MST: Multiple Spanning Trees CIST: Common and Internal Spanning Tree MSTI: Multiple Spanning Tree Instance BPDU: Bridge Protocol Data Unit In this document, unless otherwise explicitly noted, when the term STP is used, it also covers MSTP. 2. The Use Case Scenario It is a common case that an RG is connected to a bridge network where STP is running. For example, geographically dispersed DSLAMs of a Broadband Network may be connected by an RG. These DSLAMs constitute a typical STP network. For the sake of network resilience, this bridge network is redundantly connected to all RG members. The scenario in Figure 2.1 illustrates this kind of connection. Mingui Zhang Expires November 3, 2013 [Page 3] INTERNET-DRAFT STP Application of ICCP May 2, 2013 +--------------+ +=============+ | | | | | | | | | +---+ | | +-----+ | | ---+CE1+--|-------|--+ PE1 | | | +---+ | | +-----+ | | | | || | | | | || ICCP | | | | || | | +---+ | | +-----+ | | ---+CE2+--|-------|--+ PE2 | | | +---+ | | +-----+ | | | | | | Multi-homed | | Redundancy | | STP Network | | Group | +--------------+ +=============+ Figure 2.1: A STP network is multi-homed to a Redundant Group. 2.1. Virtual Root Bridge With ICCP, the whole RG will be virtualized to be a single bridge. The RG pretends that the ports connected to the STP network are from the same root bridge. All these ports emit configuration BPDU with the highest root priority to trigger the construction of the spanning tree. In this way, the STP will always break a loop within the multi- homed STP network. Each RG member has its BridgeIdentifier (the MAC address). The least significant one is elected as the BridgeIdentifier of the 'vitualized root bridge'. 3. Spanning Tree Protocol Application TLVs This section specifies the ICCP TLVs for the Spanning Tree Protocol application. 3.1. STP Connect TLV This TLV is included in the RG Connect message to signal the establishment of STP application connection. Mingui Zhang Expires November 3, 2013 [Page 4] INTERNET-DRAFT STP Application of ICCP May 2, 2013 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Protocol Version |A| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Optional Sub-TLVs | ~ ~ | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Connect TLV" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Protocol Version The version of this particular protocol for the purposes of ICCP. This is set to 0x0001. - A bit Acknowledgement Bit. Set to 1 if the sender has received a STP Connect TLV from the recipient. Otherwise, set to 0. - Reserved Reserved for future use. - Optional Sub-TLVs There are no optional Sub-TLVs defined for this version of the protocol. 3.2. STP Disconnect TLV Mingui Zhang Expires November 3, 2013 [Page 5] INTERNET-DRAFT STP Application of ICCP May 2, 2013 This TLV is used in an RG Disconnect Message to indicate that the connection for the STP application is to be terminated. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Optional Sub-TLVs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Disconnect TLV" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Optional Sub-TLVs The only optional Sub-TLV defined for this version of the protocol is the "STP Disconnect Cause" TLV defined next: 3.2.1. STP Disconnect Cause TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Disconnect Cause String | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Disconnect Cause TLV" Mingui Zhang Expires November 3, 2013 [Page 6] INTERNET-DRAFT STP Application of ICCP May 2, 2013 - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Disconnect Cause String Variable length string specifying the reason for the disconnect. Used for network management. 3.3. STP Config TLVs The STP Config TLVs are sent in the RG Application Data message. When a STP Config TLV is received by a peering RB member, it SHOULD synchronize the configuration information contained in the TLV. TLVs specified from section 3.3.1 through section 3.3.9 contains such kind of configuration information. 3.3.1. STP System Config This TLV announces the PE's STP System Parameters to the RG peers. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ROID | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAC Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP System Config" - Length Length of the MAC address, which is 6 octets. Mingui Zhang Expires November 3, 2013 [Page 7] INTERNET-DRAFT STP Application of ICCP May 2, 2013 -ROID As defined in the ROID section of [ICCP]. - MAC Address The MAC address of the sender. This MAC address is set to the BridgeIdentifier of the sender, as defined in [802.1q] section 13.23.2. The the least significant unsigned BridgeIdentifier is used as the MAC address of the Virtual Root Bridge mentioned in Section 2.1. 3.3.2. STP Topology Changed Instances This TLV is used to report the Topology Changed Instances to other members in the RG. The receiver RG member SHOULD enforce the Topology Change to its port connected to the STP network, including the flush out of MAC addresses relevant to the instances listed in this TLV. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | InstanceID List | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Topology Changed Instances" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - InstanceID List The list of the instances whose topology is changed as indicated by the Topology Change Notification (TCN) Messages as specified in [802.1q] section 13.14. 3.3.3. STP CIST Root Time Mingui Zhang Expires November 3, 2013 [Page 8] INTERNET-DRAFT STP Application of ICCP May 2, 2013 This TLV is used to report the Value of CIST Root Time to other members in the RG. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MaxAge | MessageAge | FwdDelay | HelloTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RemainingHops | +-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP CIST Root Time" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - MaxAge The Maximum Age of this TLV. - MessageAge The actual age of this TLV. - FwdDelay The delay before the port enters the forwarding status. - HelloTime The interval between two continuous configuration BPDUs. - RemainingHops The remaining hops of this TLV 3.3.4. STP MSTI Root Time Mingui Zhang Expires November 3, 2013 [Page 9] INTERNET-DRAFT STP Application of ICCP May 2, 2013 This TLV is used to report the Value of MSTI Root Time to other members in the RG. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | InstanceID | RemainingHops | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP MSTI Root Time" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - InstanceID The instance identification number of the MSTI. - remainingHops The remaining hops of this TLV 3.3.5. STP Region Name This TLV is used to report the Value of Region Name to other members in the RG. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Region Name | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. Mingui Zhang Expires November 3, 2013 [Page 10] INTERNET-DRAFT STP Application of ICCP May 2, 2013 - Type set to TBD for "STP Region Name" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Region Name The Name of the MST Region. 3.3.6. STP Revision Level This TLV is used to report the Value of Revision Level to other members in the RG. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Revision Level | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Revision Level" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Revision Level The Revision Level as specified in [802.1q] section 3.21; 3.3.7. STP Instance Priority This TLV is used to report the Value of Instance Priority to other members in the RG. Mingui Zhang Expires November 3, 2013 [Page 11] INTERNET-DRAFT STP Application of ICCP May 2, 2013 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Pri | InstanceID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Instance Priority" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Pri The Instance Priority - InstanceID The instance identification number of the MSTI. 3.3.8. STP Configuration Digest This TLV is used to report the Value of STP VLAN Instance Mapping to other members in the RG. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Configuration Digest | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type Mingui Zhang Expires November 3, 2013 [Page 12] INTERNET-DRAFT STP Application of ICCP May 2, 2013 set to TBD for "STP Configuration Digest" - Length Length of the STP Configuration Digest which is 16 octets. - Configuration Digest As specified in [802.1q] section 13.7. 3.4. STP Synchronization Request TLV The STP Synchronization Request TLV is used in the RG Application Data message. This TLV is used by a device to request from its peer to re-transmit configuration or operational state. The following information can be requested: - system configuration and/or state - configuration and/or state for a specific port The format of the TLV is as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U|F| Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Request Number |C|S| Request Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Port Number | Actor Key | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - U and F Bits Both are set to 0. - Type set to TBD for "STP Synchronization Data TLV" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Request Number 2 octets. Unsigned integer uniquely identifying the request. Used to match the request with a response. The value of 0 is Mingui Zhang Expires November 3, 2013 [Page 13] INTERNET-DRAFT STP Application of ICCP May 2, 2013 reserved for unsolicited synchronization, and MUST NOT be used in the STP Synchronization Request TLV. - C Bit Set to 1 if request is for configuration data. Otherwise, set to 0. - S Bit Set to 1 if request is for running state data. Otherwise, set to 0. - Request Type 14-bits specifying the request type, encoded as follows: 0x00 Request System Data 0x01 Request Port Data 0x3FFF Request All Data - Port Number 2 octets. When Request Type field is set to 'Request Port Data', this field encodes the STP Port Number for the requested port. When the value of this field is 0, it denotes that all ports, whose STP Key is specified in the "Actor Key" field, are being requested. - Actor Key 2 octets. STP Actor key for the corresponding port. When the value of this field is 0 (and the Port Number field is 0 as well), it denotes that information for all ports in the system is being requested. 3.5. STP Synchronization Data TLV The STP Synchronization Data TLV is used in the RG Application Data message. A pair of these TLVs is used by a device to delimit a set of TLVs that are being transmitted in response to an STP Synchronization Request TLV. The delimiting TLVs signal the start and end of the synchronization data, and associate the response with its corresponding request via the 'Request Number' field. The STP Synchronization Data TLVs are also used for unsolicited advertisements of complete STP configuration and operational state data. The 'Request Number' field MUST be set to 0 in this case. Mingui Zhang Expires November 3, 2013 [Page 14] INTERNET-DRAFT STP Application of ICCP May 2, 2013 This TLV has the following format: - U and F Bits Both are set to 0. - Type set to TBD for "STP Synchronization Data TLV" - Length Length of the TLV in octets excluding the U-bit, F-bit, Type, and Length fields. - Request Number 2 octets. Unsigned integer identifying the Request Number from the "STP Synchronization Request TLV" which solicited this synchronization data response. - Flags 2 octets, response flags encoded as follows: 0x00 Synchronization Data Start 0x01 Synchronization Data End 4. Security Considerations This document raises no new security issues. 5. IANA Considerations The types used by the application TLVs defined in Section 3 should be assigned. 6. References 6.1. Normative References [ICCP] L. Martini, S. Salam, et al, "Inter-Chassis Communication Protocol for L2VPN PE Redundancy", draft-ietf-pwe3-iccp-09.txt, work in progress. 6.2. Informative References [802.1q] "IEEE Standard for Local and Metropolitan Area Networks--- Mingui Zhang Expires November 3, 2013 [Page 15] INTERNET-DRAFT STP Application of ICCP May 2, 2013 Virtual Bridged Local Area Networks.". IEEE Std 802.1 Q-2005, May 19, 2006. Mingui Zhang Expires November 3, 2013 [Page 16] INTERNET-DRAFT STP Application of ICCP May 2, 2013 Author's Addresses Mingui Zhang Huawei Email: zhangmingui@huawei.com Huafeng Wen Huawei Email: wenhuafeng@huawei.com Mingui Zhang Expires November 3, 2013 [Page 17]