On 09/12/13 14:47, Markus H wrote:

I don't think microbursts are that much of a problem for us. I at least
don't see them impacting the VM host sending a backup to the file server,

That's *exactly* the sort of thing that microbursts tend to impact.

The basic problem is:

 port A sends to port B at 1Gbit/sec
 port C sends a burst of 10 packets to port B every X seconds
 port A TCP flow drops, and recovers relatively slowly
 repeat
 A->B bulk throughput is a small fraction of the link rate

or even several of us pushing photos/videos from an event we attended onto
the owncloud instance. (If anyone however has some nice article that I
should read on microbursts feel free to send a link my way.)

There's extensive discussion on this in the list archives, but the basic idea is simple; tiny bursts of traffic, often back-to-back / linerate (e.g. as a result of 10kb of data being send via TSO NIC offload) cause other TCP flows to sawtooth.

They may not be a problem for you - we used the 3750s for years without problems - but don't underestimate how annoying they can be.
_______________________________________________
cisco-nsp mailing list  [email protected]
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

Reply via email to