On Wednesday 29 Sep 2010, Lee, John (Sydney) wrote: > Do you mean that if I could define 30 channels in span 1 for example, then > span 1 is set to E1? > > If not, then it is T1.
Yes! That's how it works. Civilised countries manage to squeeze 30 B-channels and two D-channels onto an ISDN line by using trinary encoding, where three "trits" represent four bits. DC balancing is achieved by using two (equal and opposite) 3-trit representations for each of the nybbles represented by unbalanced symbols, and sending one or the other depending whether the imbalance is positive or negative. This gives 33% extra capacity as compared to simply sending ones as positive or negative in strict alternation, hence 30 + 2 aot 23 + 1. -- AJS -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
