LOS ANGELES—This is the second installment of a contribution from Jim DeFilippis on SDI versus IP. For Part 1, see “Which Switch is Which?” The second tale-of-the-tape issue is delay or latency. There ...

ShenQingguo has been an Associate Professor at the Institute ofCommunications Engineering, Nanjing, China since 1995. He currentlyteaches courses on computer networks and mobile computer networks.He ...