Pseudo-Wire Edge-to-Edge (PWE3) Working Group Stewart Bryant Internet Draft Cisco Systems Document: Expires: April 2003 October 2002 PWE3 Common Terminology Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of section 10 of RFC2026. 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/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document defines the terminology common to PWE3 drafts. Bryant. Informational [Page 1] INTERNET DRAFT draft-bryant-pwe3-terms-00.txt October 2002 Table of Contents Status of this Memo.......................................... 1 1. Introduction............................................. 3 2. Terminology.............................................. 3 3. IANA considerations...................................... 5 4. Security Considerations.................................. 6 Bryant. Informational [Page 2] INTERNET DRAFT draft-bryant-pwe3-terms-00.txt October 2002 1. Introduction The following is background text for this revision only: At IETF-54 it was agreed that a single PWE3 terminology document would be generated defining common terms. My understanding is that PWE3 authors would then remove these common terms from their drafts thereby removing any conflicting definitions. I have derived these terms from a combination of the protocol- layering draft and the framework draft. I plan to put out a revised version before IETF-55, that will include feedback received. The draft now continues as normal: This document attempts to define the common terms used in PWE3. Documents produced by the IETF PWE3 WG use this common terminology, but may define additional terms unique to their technical area. 2. Terminology This document uses the following definitions of terms. These terms are illustrated in context in Figure 2. Attachment Circuit The circuit or virtual circuit attaching (AC) a CE to a PE. Applicability Each PW service will have an Applicability Statement (AS) Statement (AS) that describes the applicability of PWs for that service. CE-bound The traffic direction where PW-PDUs are received on a PW via the PSN, processed and then sent to the destination CE. CE Signaling Messages sent and received by the CEs control plane. It may be desirable or even necessary for the PE to participate in or monitor this signaling in order to effectively emulate the service. Customer Edge (CE) A device where one end of a service originates and/or terminates. The CE is not aware that it is using an emulated service rather than a native service. Bryant. Informational [Page 3] INTERNET DRAFT draft-bryant-pwe3-terms-00.txt October 2002 Encapsulation, Each PW service will have an Encapsulation, Emulation and Emulation and Maintenance Document (EEMD) Maintenance that described the particulars of PWs for Document (EEMD) that service, as well as the degree of faithfulness to that service. Author note - is EEMD used anywhere other than in the architecture or framework document? Can it be removed? Forwarder (FWRD) A PE subsystem that selects the PW to use to transmit a payload received on an AC. Fragmentation The action of dividing a single PDU into multiple PDUs before transmission with the intent of the original PDU being reassembled elsewhere in the network. Fragmentation may be performed in order to allow sending of packets of a larger size than the network MTU which they will traverse. Inter-working Interactions between networks, between end systems, or between parts thereof, with the aim of providing a functional entity capable of supporting an end-to-end communication. Inter-working A function that facilitates inter-working Function (IWF) between two dissimilar services. NSP may perform the IWF function. Author note - is IWF used anywhere other than in the architecture or framework document? Can it be removed? Maximum transmission The packet size (excluding data link header) unit (MTU) that an interface can be transmit without needing to fragment. Native Service Processing of the data received by the PE Processing (NSP) from the CE before presentation to the PW for transmission across the core. Packet Switched Within the context of PWE3, this is a Network (PSN) network using IP or MPLS as the mechanism for packet forwarding. Protocol Data The unit of data output to, or received Unit (PDU) from, the network by a protocol layer. Provider Edge (PE) A device that provides PWE3 to a CE. Bryant. Informational [Page 4] INTERNET DRAFT draft-bryant-pwe3-terms-00.txt October 2002 PE-bound The traffic direction where information from a CE is adapted to a PW, and PW-PDUs are sent into the PSN. PE/PW Maintenance Used by the PEs to set up, maintain and tear down the PW. It may be coupled with CE Signaling in order to effectively manage the PW. Pseudo Wire (PW) A mechanism that carries the essential elements of an emulated service from one PE to one or more other PEs over a PSN. PW End Service The interface between a PE and a CE. This (PWES) can be a physical interface like a T1 or Ethernet, or a virtual interface like a VC or VLAN. Pseudo Wire A mechanism that emulates the essential Emulation Edge to attributes of service (such as a T1 leased Edge (PWE3) line or frame relay) over a PSN. Pseudo Wire PDU A PDU sent on the PW that contains all of (PW-PDU) the data and control information necessary to emulate the desired service. PSN Tunnel A tunnel across a PSN inside which one or more PWs can be carried. PSN Tunnel Used to set up, maintain and tear down the Signaling underlying PSN tunnel. PW Demultiplexer Data-plane method of identifying a PW terminating at a PE. Tunnel A method of transparently carrying information over a network. 3. IANA considerations There are no IANA considerations for this document. Bryant. Informational [Page 5] INTERNET DRAFT draft-bryant-pwe3-terms-00.txt October 2002 4. Security Considerations The other documents produced by PWE3 will be manually checked to ensure that they do not re-define any of these terms. Editors' Addresses Stewart Bryant Cisco Systems, 4, The Square, Stockley Park, Uxbridge UB11 1BL, United Kingdom. Email: stbryant@cisco.com Full copyright statement Copyright (C) The Internet Society (2002). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS Bryant. Informational [Page 6]