I am bridging FDDI over ATM (sonet oc3 net) and need to increase window size in IP. Traces show window size at 8136 and frames are about 4k so I can only send one frame without a definite responce being returned. This causes low FDDI utilization and poor performance as propagation delay over WAN cannot be avoided. Can anyone provide instruction on an HP unix machine on how to increase window size or performance in this environment Scott Jones