> It might help my understanding if I knew what was different about 10mb and > 100mb ethernet other than the maximum throughput. For example, does 100mb > use a greater frequency bandwidth, does it send more pulses per unit time, > or what? more pulses per unit time, I believe. this is why 100Mbit Ethernet has a maximum network diameter (distance between the two farthest points) only 1/10th as big as 10Mbit; all the other nodes on the network need to be able to detect that someone has sent something at the identical moment, by the time they finish sending. since the minimum ethernet packet size is 64bytes (I think...), the cable between any two points has to be short enough that the first bit gets to the far side of the network by the time that the last bit is sent. otherwise you have the possibility of an undetected collision, and corrupted data. since 100Mb ethernet sends data pulses only 1/10th as long as long as 10Mb; you only get 1/10th as much time to detect a collision. Carl Soderstrom. -- Network Engineer Real-Time Enterprises (952) 943-8700