RFC 755 (rfc755) - Page 2 of 12

Assigned numbers

RFC 755                                                       3 May 1979
IEN 93                                                  Assigned Numbers
Link Numbers



                         ASSIGNED LINK NUMBERS

   The word "link" here refers to a field in the original ARPANET
   Host/IMP interface leader.  The link was originally defined as an 8
   bit field.  Some time after the ARPANET Host-to-Host (AHHP) protocol
   was defined and, by now, some time ago the definition of this field
   was changed to "Message-ID" and the length to 12 bits. The name link
   now refers to the high order 8 bits of this 12 bit message-id field.
   The low order 4 bits of the message-id field are to be zero unless
   specifically specified otherwise for the particular protocol used on
   that link.  The Host/IMP interface is defined in BBN report 1822 [2].

   Link Assignments:

      Decimal   Octal     Description                         References
      -------   -----     -----------                         ----------
      0         0         AHHP Control Messages                    [1,3]
      1         1         Reserved
      2-71      2-107     AHHP Regular Messages                    [1,3]
      72-151    110-227   Reserved
      152       230       PARC Universal Protocol
      153       231       TIP Status Reporting
      154       232       TIP Accounting
      155-158   233-236   Internet Protocol             [35,36,42,43,44]
      159-191   237-277   Measurements                              [28]
      192-195   300-303   Message Switching Protocol               [4,5]
      196-255   304-377   Experimental Protocols
      224-255   340-377   NVP                                     [1,39]





















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