We have some web security appliances connected via 1Gb/s copper to 6748 Line cards in a Cat 6513 with Sup720. The appliance manufacturer assures us the appliances can cope with traffic well above 800Mb/s (The traffic is always equal in both directions)
We have previously seen traffic levels > 500Mb/s for a period without any issue. However more recently we have seen elevated response times to the appliances as the bandwidth approaches 400Mb/s. Investigations show we're seeing outbound drops now as we approach those speeds. We have qos enabled on the chassis but these particular ports have up till now been left at default queue setting. All the traffic is in queue 0 which currently only has 50% of the queues. We have now amended that to 90% but will have to wait until the next peak in traffic to judge the impact. However I'm a little unsure why we previously saw no issue @ 500Mb/s but do now @ 400Mb/s. Nothing has changed on the appliances - however we did remove some other redundant 6148A cards to allow the switch to operate in full DFC mode. I don't have outbound errors/drops from before the cards were removed but response times certainly didn't show the increase. Is it likely/possible that when operating in CFC mode the chassis/CFC was effectively buffering the packets better before hitting the switchport.but now they're arriving directly via DFC the individual port buffers are struggling ?. If that theory doesn't hold water..any other suggestions ? What bi-directional throughput is reasonable to expect from a 6748 port ? (If it makes any difference the chassis build has 1x original ACE, 3xFWSM, 2x6704 ,1x6708 and 2x6748+ 1 xSup720. All the line cards now have DFC 3B (or 3C for 6708) where appropriate) Thanks Dean _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
