[Asterisk-Dev] Channel bank w/ bri card and Zaptel

[George Bean]

> 4:1 TDM is where 4 BRI lines share a DS0 for the D channel
> 
> 3DS0 BRITE is where the ISDN BRI uses 3 DS0 channels and the D is on a
> DS0 of it's own.
> 
> Don't know more, but this hopefully will help if you want to shake
down
> some documentation more than what this says. It would be nice if both
> kinds of muxing are available.
> 
> Out of curiousity, wouldn't this be the same type of information as is
> in the D channel of a PRI, and therefore maybe mostly implemented
> already in libpri?
> 
The BRITE configuration is much more prevalent than the 4:1 TDM version
among several manufacturers of ISDN extension equipment. The D channel
information contained in the third DSO of the BRITE grouping is 1/23 of
the PRI signaling channel. The 4:1 TDM signaling DSO contains 4/23 of a
PRI signaling channel. It's conceivable that the libpri could be
modified to handle the BRITE/4:1 configuration. This would entail adding
code to interleave D channel information from the dedicated DS0's on the
T1 and a configuration line to group DS0's and designate DS0's carrying
D channel information. Creating a BRITE/4:1 version of libpri would
definitely provide * users with much needed options for connecting ISDN
desksets as well as equipment such as video conferencing systems and 56K
modem terminations.

Regards,
George Bean
Puwaba Technologies