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Re: backbone routers' priority settings for ICMP & UDP

  • From: Scott Whyte
  • Date: Wed Feb 04 11:28:58 1998

Marc, I'd have to agree, ICMP is more for flow control than congestion
control. A source quench is to slow a fast machine from overrunning a slow
machine, not preventing all flows from going through one link. One then
wonders how well Win95 implements source quench, if at all. 

One (weak) metaphor is that traffic lights at an intersection are for flow
control, while the traffic lights to get onto the freeway (common here in
California) are for congestion control... 

On Tue, 3 Feb 1998, Marc Slemko wrote:

> Sure, hosts can generate them, but that is seldom of much utility
> (especially in the discussion here about network congestion control as
> opposed to host/processing congestion control)  because the network is
> more often the backlog than the host, and the host can't generate messages
> saying the network is congested. 
> ICMP messages are not a commonly used or particularily useful method of
> congestion control on the Internet today. 

Scott Whyte 408.527.5713         |Any opinions expressed herein are 
Network Supported Accounts (NSA) |mine and not cisco's...
CCIE 3340                        |
                                 | "Eschew Obfuscation"