RFC 795 (rfc795) - Page 1 of 4

Service mappings

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Network Working Group                                          J. Postel
Request for Comments:  795                                           ISI
                                                          September 1981
                            SERVICE MAPPINGS
                            ----------------


This memo describes the relationship between the Internet
Protocol (IP) [1] Type of Service and the service parameters of specific
networks.

The IP Type of Service has the following fields:

   Bits 0-2:  Precedence.
   Bit    3:  0 = Normal Delay,      1 = Low Delay.
   Bits   4:  0 = Normal Throughput, 1 = High Throughput.
   Bits   5:  0 = Normal Relibility, 1 = High Relibility.
   Bit  6-7:  Reserved for Future Use.

      0     1     2     3     4     5     6     7
   +-----+-----+-----+-----+-----+-----+-----+-----+
   |                 |     |     |     |     |     |
   |   PRECEDENCE    |  D  |  T  |  R  |  0  |  0  |
   |                 |     |     |     |     |     |
   +-----+-----+-----+-----+-----+-----+-----+-----+

   111 - Network Control
   110 - Internetwork Control
   101 - CRITIC/ECP
   100 - Flash Override
   011 - Flash
   010 - Immediate
   001 - Priority
   000 - Routine

The individual networks listed here have very different and specific
service choices.

















Postel
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