PTP 400 series and 3Com SS II 3300 switches

Hello list,

I am running a PTP 400 series lite link as a LAN extension for a customer. The link is using 5.4 GHz and is just over a mile with excellent wireless characteristics- it runs at the highest modulation mode consistently. The problem I’m having is on the ethernet side of the links. One side of the link is connected to a 3Com SuperStack II 3300 switch, the other is connected to a 3Com Corebuilder 3500 switch. When running at 100mbps full or half duplex, either with autonegotiation enabled or disabled, I get checksum errors on the ethernet interfaces. The cabling between the switches and the radios is approx 150 feet of Cat5e STP with Altelicon Cat-6 surge supressors at the radio module and near the switch on each end. The only way I can get rid of the ethernet errors is to drop down to 10 mbps. I have replaced the entire cable run and all connectors at one end of the link with no change in results. Is this a problem that anyone has seen before with the 3com switches?

I’d suspect that the speed/duplex negotiation is experiencing difficulty due to the arrestors?

Try without them.

I have the same equipment set up with Cisco switches on a different network (same cable, same arrestors) and have very few errors- less than 0.1%. This is leading me to beleive that the 3Com switches are the culprit.