[e2e] a new IRTF group on Transport Models

Cannara cannara at attglobal.net
Wed Jun 8 17:06:27 PDT 2005

Well Noel, I actually did mention Quench, but it's not exactly a vernier
adjustment, now is it?...

"The source quench message is a request to the host to cut back the rate at
which it is sending traffic to the internet destination.  The gateway may send
a source quench message for every message that it discards.  On receipt of a
source quench message, the source host should cut back the rate at which it is
sending traffic to the specified destination until it no longer receives
source quench messages from the gateway.  The source host can then gradually
increase the rate at which it sends traffic to the destination until it again
receives source quench messages.  The gateway or host MAY send the source
quench message when it approaches its capacity limit rather than waiting until
the capacity is exceeded.  This means that the data datagram which triggered
the source quench message may be delivered."

Plus, there are those who think it a poor idea anyway.  It obviously has no
concept of management that's aware of admission commitments, etc.  Instead,
it's a knee-jerk reaction, which requires long delays after the event, in
terms of the quenched sources:

"The source host can then gradually increase the rate at which it sends

Hardly a congestion-management system, since the sources may remain slow far
longer than needed.  In other words, it's at best a stopgap/fallback last

I've never had anyone say I "know everything".  Thanks!  All I know is from
experience in networking starting with Xerox Ethernet/XNS, Zilog Znet, the AMD
Lance and telecom chip designs of '84, 3Com stuff, including TCP/IP, plus
consulting with a few folks on networking for all types of LANs/WANs &
protocols for the past 15 years or so.  

In fact, we consultants love TCP/IP and the Internet, because it provides such
a good living solving problems for people at good hourly rates -- just did
that today!  Never could have made as much if Netware or Vines were still
popular.  :]

The "coward" statement is just what any good shrink will explain to you -- a
coward lives every day knowing that about him/her self, which is exactly how
whatever God(s) one believes in deal with cowards.


Noel Chiappa wrote:
>     > From: Cannara <cannara at attglobal.net>
>     > the Internet designers never considered anything but IP and a few hosts
>     > ...
>     > Admission & flow control at the network layer? What's that?
>     > ...
>     > Whether or not TCP is ever given accurate info to distinguish physical
>     > loss from true congestion matters little.
> Gee, Alex, since you seem to know everything (in addition to being smarter
> than all the early Internet people put together), perhaps you can explain to
> me what ICMP type 4 messages are supposed to do...
> (And, for the rest of you, does anyone know how CYCLADES handled congestion?
> I have the CYCLADES book, so I could go look it up, but I was hoping someone
> could save me the trouble.)
>     > If there are such good souls ready to stand up and do what needs be
>     > done, I applaud you. Remember, courage men/women, God hates a coward.
> I would cheerfully say what I really think, but alas, I'm afraid the list
> maintainers would likely chastise me (rightly) for ad hominem attacks.
>         Noel

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