Hi group, I am doing a quick test with the following: PC1 --- 3COM 8 port FE switch --- PC2 Both PCs running Win2000 Server. TCP tests are just fine (around 95Mbps), but UDP tests can not get higher than 1Mbps. I have tried modifying the socket buffer and the datagram length but I get the same. With the Ethereal analyser I see that packets are sent every 10ms. Regards, jordi.