On 03/10/2011 20:57, Paul Cosgrove wrote: > I think you may have an error there. Your calculations suggest that > traffic in on a 1Gbps interface will fill a 1.3M Byte receive buffer in a > little under a 1/10 of a second. While the preamble and inter frame gap > will slow the buffer fill rate (the degree depending on the packet size), > that seems very slow.
yeah, I was sloppy with language there, and ignored ipg. I also assumed 8 bytes per bit, maximum buffers assigned to tx data (in fact it's 1.2M tx and 166k rx on a 6748-ge blade), flow control disabled and I wasn't clear about the exact direction of data, and so on... The point was that if you allow port contention (i.e. by enabling flow control) and if you only look at 5 minute port counters, you are only guaranteed not to drop packets at ridiculously low apparent data transfer rates. 5 minutes is an eternity in the life of a switch. Bah, I should have known not to pick nits like this in public! It never turns out well. :-( Nick _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
