Yes sir Victor. I was merely trying to keep it very simple, but ended up asuming too much. Actually, alaw can't be used by T1 due to robbed bit practices in T1, if I remember that correctly.
I was trying to show that the encoding schemes follow the circuit types. To be fully correct, in my humble opinion, T1 and E1 are "hardware" formats and the DS-nn series are "signaling" formats. And I've had quite a few lively discussions as to the difference between T1 and DS1. T1 is simply circuit constructed to respond optimally to a DS-1 signal. I also seem to remember that little Costa Rica is T1. Can't remember about the rest of the Caribbean, though. Converting between alaw and mulaw is done with an accepted amount of distortion since the bits don't quite match between the two. IIRC, it's done with a simple lookup table. On Tue, 8 Sep 1998, Victor L. Boersma wrote: > > > u-law is T1 > > > a-law is E1 > > ????????????????????????????????????????????????????????? > > > mu and A- law are encoding schemes. > > T1 and E1 are transmission schemes (24 and 30 channels). > > mu-law encoding and transmission at the DS1-level are what AT&T thought > best and is mainly used in North America (including the Carribean and > Mexico) > and Japan. > > A-law encoding and E1 digital transmission is what most of the rest of the > world is going to, as they go digital. > > No reason I know of why you couldn't transmit mu-law encoding over an E1 > pipe. > Rational for maintaining the difference is same as that for measuring > things in relation to the extremities of some long dead king of England. > > As you go from an A-law environment to a mu-law environment, you've got to > translate. By agreement, those using mu-law will translate to A-law before > it goes across. Those using A-law need not translate by the same agreement > and the stuff is translate when it arrives in the mu-law environment. Same > for T1 and E1. > > Ciao, > > > Vic >
