RFC 795 (rfc795) - Page 1 of 4
Service mappings
Alternative Format: Original Text Document
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