Re: [Ips] throttling the initiator

Paul Koning <pkoning@equallogic.com> Tue, 20 February 2007 14:42 UTC

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Date: Tue, 20 Feb 2007 09:42:18 -0500
From: Paul Koning <pkoning@equallogic.com>
To: Quicksall_iSCSI@Bellsouth.net
Subject: Re: [Ips] throttling the initiator
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>>>>> "Eddy" == Eddy Quicksall <Quicksall_iSCSI@Bellsouth.net> writes:

 Eddy> As resources become scarce I would like to throttle the
 Eddy> initiator back. I thought about reducing MaxCmdSN but if I do
 Eddy> that the initiator will just ignore it. 

...or call it a protocol error...

That's the problem with flow control in most protocols: once you sent
out permission to transmit, you can't take it back.

So the best you can do is throttle back the initiator by not sending
it as much new credit when it uses up what you gave it already.
That's generally ok; if the initiator is transmitting you can do this,
and if it's not transmitting it's not using up resources anyway.

    paul


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