    NWG/RFC# 717                                 JBP  30-JUN-76 16:58  35873
    Assigned Network Numbers

    Network Working Group                                         Jon Postel
    Request for Comments 717                                         SRI-ARC
    NIC 35873                                                    1 July 1976

                            Assigned Network Numbers

    This note specifies the numbers assigned to identify networks for use in
    the inter-network protocol experiments.  Additional Numbers are assigned
    by Jon Postel [POSTEL@ISIC or (415) 326-6200 x3718].

    Assigned Network Numbers

      Name          Decimal     Octal

      ----------    -------     -----

      BBNRCCnet        3           3
      SanFranPRnet     7           7
      ARPANET         10          12
      BostonPRnet     11          13

    Internetwork Header Format

      For convenience the current Internetwork protocol header and TCP
      headers are reproduced here:

      Octet Bit     Use                      (Width)

        --- Beginning of protocol-independent information ---

        0           Destination net          (8)
        1-3         Destination host         (24)
        4           Source net               (8)
        5-7         Source host              (24)
        8-9         Data length in octets    (16)
        10          Header length in octets  (8)
        11   0-3    Format                   (4)
          This field selects the appropriate gateway processing and is used
          to dispatch the packet to the appropriate protocol module in the
          destination.  The following values are defined for this field:
            0 -- Escape; protocol is specified by a subsequent field
            1 -- TCP
            2 -- Secure TCP
            3-16 -- Not allocated
            17 -- Cross internet debugging

       --- End of protocol-independent information

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    NWG/RFC# 717                                 JBP  30-JUN-76 16:58  35873
    Assigned Network Numbers

       --- Beginning of TCP specific information ---

       11   4-7     Protocol version         (4)
       12-15        Sequence number          (32)
       16-17        Window                   (16)
       18-20        Control (as before)      (24)
       21-23        Destination port         (24)
       24           Packet label for debugging(8)
       25-27        Source port              (24)
       28-31        Acknowledgement number   (32)
       32-33        Checksum                 (16)
       34-          Data

       --- End of TCP specific information ---

       --- Beginning of short TCP specific information ---

       11   4-7     Protocol Version         (4)
       12-25        Sequence number          (32)
       16           Destination KID          (8)
       17           Source KID               (8)
       18-19        Control (no special function field)(16)
       20-          Data

       --- End of short TCP specific information ---

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