Dropped Frames?

[BertimusMaximus]

I am trying to troubleshoot an application that appears to have frames dropping when it traverses a 7206 via fast ethernet interfaces.

I have enable port mirroring on the switches that connect to the router ports. I have sniffed the incoming traffic and see the frame enter the router. However, on the outgoing port I don't see the frame. This happens about 2 or 3 times out of 350 so it is intermittent.

The router interfaces and switch ports are all clean. I applied some ACLs and they show the same number of frames exiting one interface as entered on the other, yet the sniffer traces never show the occaisional missing frame.

Any ideas?

[wong34539]

Network congestion can lead to reduced performance and inefficient use of LAN/WAN bandwidth.

Hence the goal is to avoid congestion wherever possible by using algorithms (such as Random Early Detection [RED] that capitalize on the adaptive nature of TCP traffic to use packet drops as a means of reducing the rate of TCP transmission. However, if you have multiple TCP sources, then dropping packets uniformly from all sources causes all of them to back off and then begin retransmission all at once. This scenario leads to waves of congestion, also referred to as "global synchronization." As seen in the diagram, this situation causes drastic drops in throughput

http://www.cisco.com/warp/public/cc/pd/iosw/ioft/ioqo/tech/qos72_wp.htm