[Asterisk-doc] Connecting to a PRI

[Mats Karlsson]

Julian Lyndon-Smith wrote:

> Euro ISDN PRI have 31 channels, 16th used for signalling

Noop, I disagree, its 30 channels for payload.

A "raw" E1 (aka. G.703) is 2.048 Mbps = 32 x 64000 bps = 32
TimeSlots/Channels.

And a framed E1 (aka. G.704+G.732, Structured G.703, 30B+D) has 30
channels for transporting and 2 for signaling/sync.
Time slot zero (TS0) is used for synchronization and TS16 is used for
signaling.

It is possible to use 31 channels but I have never seen that in use for
voice purpose but it's quite common in datacom.


Some references:
http://www.syncuniversity.org/drsync/q34.php
http://telecom.tbi.net/e1_frm.html
http://telecom.tbi.net/t1_frm.html


/Mats