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To: grog@lemis.de (Greg Lehey)
cc: helg@tav.kiev.ua (Oleg N Panashchenko),
        hackers@FreeBSD.ORG (FreeBSD Hackers)
Subject: Re: IP question: who should return ENOBUFS? 
In-reply-to: Your message of "Sat, 22 Jun 1996 13:16:26 +0200."
             <199606221116.NAA14679@allegro.lemis.de> 
From: David Greenman <davidg@root.com>
Reply-To: davidg@root.com
Date: Sat, 22 Jun 1996 17:33:21 -0700
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>I'd consider that a workaround.  We need to change the congestion
>avoidance algorithm to something that works.  In the meantime, this
>"bug fix" in ip_output must be removed.

   I disagree. The problem is in the way that the ISDN driver decides to
dequeue packets. As packets go out, the number of packets on the queue 
should decrease until they fall below the threshold. If they don't decrease,
then there's a bug that needs to be fixed. Note that the case of the Digiboard
driver is likely different. That one seems to indicate stuck flow control
and is probably caused by a race condition in dealing with rts/cts in the
interrupt routine.

-DG

David Greenman
Core-team/Principal Architect, The FreeBSD Project