Hank,

How do carriers handle E3 to T3 conversions? What equipment is used? I have heard that trans-Atlantic carriers sell E3s to Europeans when in fact it is a T3 with T3 costs passed on the customer and merely convert the line from T3 to E3 - thereby causing 11Mb/sec of b/w to be wasted. Any truth to that?

The model over here for the newer carriers seems to be: * Buy in 45Mb chunks or larger * Either mux to E1s (2Mb/s) or run layer 2 (ATM over it) or sell whole * Sell large circuits to the US as T3s not E3s We buy our transatlantic stuff with T3 ports either end, all our domestic private circuits as T3s, and everything else internationally is carried on circuits which use SDH and the "T" hierarchy. May be I'm unusual in this respect, but I know people who have bought from BT and got T3s too. No, I don't know why at the E1/T1 level E1 is the preferred way of doing it. -- Alex Bligh GX Networks (formerly Xara Networks)