backbone routers' priority settings for ICMP & UDP

Tue Feb 3 20:39:20 UTC 1998

>> ICMP in general is or should be given higher priority, since it is
>> necessary for congestion control.  Echo requests (pings) could be thrown
>
>Please, tell me of this magic ICMP that is used for congestion control.
>Obsolete things that are now recommended against don't count.

Where is ICMP made obsolete or recommended against?  I don't see it.

>From rfc1812:

   4.3 INTERNET CONTROL MESSAGE PROTOCOL - ICMP ...........   52
   4.3.1 INTRODUCTION .....................................   52
   4.3.2 GENERAL ISSUES ...................................   53
   4.3.2.1 Unknown Message Types ..........................   53
   4.3.2.2 ICMP Message TTL ...............................   53
   4.3.2.3 Original Message Header ........................   53
   4.3.2.4 ICMP Message Source Address ....................   53
   4.3.2.5 TOS and Precedence .............................   54
   4.3.2.6 Source Route ...................................   54
   4.3.2.7 When Not to Send ICMP Errors ...................   55
   4.3.2.8 Rate Limiting ..................................   56
   4.3.3 SPECIFIC ISSUES ..................................   56
   4.3.3.1 Destination Unreachable ........................   56
   4.3.3.2 Redirect .......................................   57
   4.3.3.3 Source Quench ..................................   57
   4.3.3.4 Time Exceeded ..................................   58
   4.3.3.5 Parameter Problem ..............................   58
   4.3.3.6 Echo Request/Reply .............................   58
   4.3.3.7 Information Request/Reply ......................   59
   4.3.3.8 Timestamp and Timestamp Reply ..................   59
   4.3.3.9 Address Mask Request/Reply .....................   61
   4.3.3.10 Router Advertisement and Solicitations ........   62

>From rfc1812:

 ICMP and IGMP are
   considered integral parts of IP, although they are architecturally
   layered upon IP.  ICMP provides error reporting, flow control,
   first-hop router redirection, and other maintenance and control
   functions.

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           Plain Aviation, Inc                  dean at av8.com
           LAN/WAN/UNIX/NT/TCPIP          http://www.av8.com
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