I have a 3945 router with a GLC-SX-MM connected to a Canoga 9145 with a 5 meter patch cable going to AT&T as a 100Mb Metro-E
Our performance is poor measuring about 4Mb up and 15Mb down. I have tried various test sites.
A show interface is showing: Half Duplex, 1Gbps, media type is SX
We are seeing a lot of output errors and TCP reassembly queue overflows
If I force the interface to full duplex I stop getting output errors and queue overflows but start getting interface resets. My performance also goes sub 1Mb
The ISP confirms their interface on the Canoga is properly configured. We have also replaced the patch cable.
Does anyone have any thoughts on possible causes?