NAP/ISP Saturation WAS: Re: Exchanges that matter...

David Schwartz davids at
Tue Dec 17 19:24:16 UTC 1996

	I'm quite curious how they handle full-duplex FDDI where 
witholding the token doesn't seem to be an option. Do they simply drop 
packets when traffic gets bursty?

	Ironically, I'd prefer they drop the packet bound for a busy port
rather than stop all incoming traffic from a port until the busy port

	If anyone has experience with NetStar's GigaRouters, especially 
in comparison to the GigaSwitches, I'd love to hear about it. You can 
reach me at davids at


On Tue, 17 Dec 1996, Dennis Ferguson wrote:

> > My (admittedly second hand) understanding is that the Gigaswitch/FDDI
> > actually has minimal amounts of buffering.  During a congestion event, it
> > simply withholds the token, resulting in buffering in the routers.  Queues
> > there eventually overflow, and ...
> This matches my understanding, though I think it understates the problem.
> Gigaswitches are essentially input-queued.  When their teeny tiny buffers
> fill they flow-control everyone to slow them down.  What this means is that

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