[Asterisk-Users] T1 Line install.. (UK Muppet)

Andrew Kohlsmith akohlsmith-asterisk at benshaw.com
Thu Apr 15 10:42:48 MST 2004


> When we had a MCI ct1, they couldn't send us proper supervised hangup on
> a loopstart encoded DS0. They claimed it to be a problem with the
> software on their switch. Their solution was to switch to groundstart.
> Our end solution was to drop them and switch to Telcove(formerly
> Adelphia) and get a PRI where we controlled the signaling with asterisk.

Again, how the hell is switching the supervision type changing anything in the 
bitstream?  You have 193 bits being sent 8000 times a second.  There is no 
grounding or reversing of a battery on any kind of T1 -- that is strictly 
FXO-side signalling.  You have 2 (SF) or 4 (ESF) bits with a CT1 to determine 
channel state.  And with ESF those extra bits are usually just duplicates of 
the original 2.  You have onhook, offhook, ringing and something I can't 
remember at the present moment.

I am positive I'm showing my T1 newbieness here but again... how does the 
switch changing their FXO signalling/supervision change the bitstream and 
"fix" CT1-related issues?

I completely understand E&M, LS, GS and all of that on the actual analog side 
-- but how does it change a damn thing on the CT1 side?

Regards,
Andrew



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