Pseudo-Wire Edge-to-Edge (PWE3) Working Group             Stewart Bryant
Internet Draft                                             Cisco Systems
Document: <draft-bryant-pwe3-terms-01.txt>
Expires: May 2003

                                                           November 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
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   The list of current Internet-Drafts can be accessed at
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Abstract

   This document defines the terminology common to PWE3 drafts.






















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   Table of Contents

   Status of this Memo..........................................    1

   1.  Introduction.............................................    3

   2.  Terminology..............................................    3

   3.  IANA considerations......................................    5

   4.  Security Considerations..................................    5








































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1.  Introduction


   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

   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.

   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.

   Maximum transmission The packet size (excluding data link header)
   unit (MTU)           that an interface can transmit without
                        needing to fragment.

   Native Service       Processing of the data received by the PE



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   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.

   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.





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   Time Domain          Synchronous bit-streams at rates defined by
   Multiplexing (TDM)   G.702.

   Tunnel               A method of transparently carrying information
                        over a network.




3.  IANA considerations

   There are no IANA considerations for this document.




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

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