draft-casati-gtp

Last Version:	draft-casati-gtp-00.txt		Tracker Entry
Date:	06-Dec-2000
Disposition:	removed

Mobile IP Working Group                                   Alessio Casati
INTERNET DRAFT                                       Lucent Technologies
 March 2000                                         Charles E. Perkins
                                                   Nokia Research Center

                    Generic Tunneling Protocol (GTP)
                        draft-casati-gtp-00.txt


Status of This Memo

   This document is a submission by the mobile-ip Working Group of the
   Internet Engineering Task Force (IETF).  Comments should be submitted
   to the MOBILE-IP@STANDARDS.NORTELNETWORKS.COM mailing list.

   Distribution of this memo is unlimited.

   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
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Abstract

   Some discussion has been lately going on on the standardization of
   GRE within the IETF. GRE has an Impact on standard track protocols
   such as Mobile IP. A Generic Tunneling Protocol (GTP) sharing the
   same format and byte order of the 3GPP GTP protocol ( 3G TS 29.060)
   benefits from the commonality of the encapsulation format used in IP
   mobility support protocols in different families of 3G standards.


. GTP HEADER

   The GTP header is a variable length header.  It is used to encapulate
   packets over any network layer or transport layer protocol (e.g.
   it can be transported over UDP/IP, in which case it SHALL use port






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                          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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Ver|*|*|*|S|R|     Type      |          Length               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Tunnel          Identifier                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       Sequence Number         |          Resv/Exp             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



   number TBD [Note:-likely to be the 3386 port, currently allocated to
   GTP defined by 3GPP]).

   Two flags signal the presence of optional fields:  the R flag and
   the S flag.  The R flag is used to signal the need to interpret
   the Reserved/Experimental field.  The S flag is used to signal the
   presence of the GTP Sequence Number field.

   If any of these flags are set, the length of the header is 12 octets
   and the fields corresponding to the flags that are set SHALL be
   evaluated by the receiver.  The bits marked with '*' are currently
   unused and reserved for experimental use and they MUST not be
   interpreted.

    -  The version field value is the version of the GTP protocol.  This
       document specifies GTP version 1.

    -  The type field defines possible different uses of the GTP. It
       shall be set to 0XFF when user traffic is transported.

    -  The length Field defines the length of the GTP encapsulated
       packet (that is the length of the user datagram encasulated using
       the GTP protocol).

    -  The Tunnel Identifier field is used as a multiplexing field.

    -  The Sequence number field defines the value of the sequence
       number of the GTP encapsulated data.  This field is present and
       SHALL be interpreted when the S Flag is set to 1.

    -  The Resv/Exp field is present and SHALL be interpreted when the R
       flag is set to 1.


Addresses

   The working group can be contacted via the current chairs:



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Internet Draft                     GTP                     10 March 2000


        Basavaraj Patil               Phil Roberts
        Nokia Corporation             Motorola
        6000 Connection Drive         1501 West Shure Drive
        M/S M8-540
        Irving, TX 75039              Arlington Heights, IL 60004
        USA                           USA
        Phone:  +1 972-894-6709       Phone:  +1 847-632-3148
        Fax :  +1 972-894-5349
        EMail:  Raj.Patil@nokia.com   EMail:  QA3445@email.mot.com

   Questions about this memo can also be directed to the authors:
           Alessio Casati                CharlesCE.oPerkinsmmunications Systems Lab
           Lucent Technologies
           Sigma Building                Nokia3Research1Center3 Fairchild Drive
           Windmill Hill Business Park
           Wiltshire, SN5 6P             MountainUView,SCaliforniaA94043
           United Kingdom
           email:  acasati@lucent.com    eMail:phcharliep@iprg.nokia.comone:  +1-650 625-2986
           phone:  +44 179388 3861       Fax:  +1 650 625-2502

































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