[Asterisk-Users] T1 E&M vs PRI question

[Andrew Kohlsmith]

Please don't post to the list using HTML.

On January 24, 2005 04:47 pm, Matt Beebe wrote:
> in-band call setup mechanism (ie: quick DTMF tones during the wink).  Each
> voice channel will actually be 56k because it uses RBS (robbed bit
> signalling -- not sure what its using this for, as the call setup is
> delivered via wink???).  As a result, this approach would also keep me from
> implementing a 56k dial-in modem service, but I could still use an
> "ordinary" modem or fax dsp to provide 33.6k dial-in.  This setup can

This is not true -- I helped run a small ISP for years on CAS T1 (robbed bit 
signaling) lines and could achieve 53kbps without even trying.  56k modems 
already detect the timeslots and can "route around" the 1/6 frame "damage" 
that inband signaling takes.

-A.