[Asterisk-Users] Interfacing T100P with Definity PBX

[Rich Adamson]

> >    I have two t100p cards installed. One card connected to the PSTN,
> > the other card is hooked to the Definity PBX with a T1 cross over
> > cable. The card connected to the PSTN works fine.
> >    The problem is with the card hooked up to the PBX. The light behind
> > the card is green, but when I dial from this card I get an error. Its
> > says it could start the D-Channel. Could someone help me out with this
> > problem
> 
> > span=1,0,0,esf,b8zs
> 
> If span 1 is the telco you want sync to be '1' not 0 -- you want the span to 
> take clock from the PSTN.  span 2 with sync '0' is right 99% of the time -- 
> most PBXes and KSUs don't have an option to be the sync source so they'll be 
> trying to sync from *, which should have it span sync set to '0' to achieve 
> this.

Andrew, I think the words came out a little different in your response
from what you were actually thinking in the last sentence above.

T1/E1 spans are really four wires; two transmit and two receive. The two
transmit wires (regardless of whether they come from a pstn, pbx, KSU, 
or whatever) always has embedded clocking within the pcm stream. There
is no way to turn that off, so its always a possible "source". What you 
probably meant was the clock (in a KSU as an example) has no options 
other then to sync _from_ the receive side of the span (as it doesn't make 
any sense generally to turn that off). It considers itself the end node, 
not the kingpin in the sync hierarchy. Your "span 2 with sync 0" is still 
correct, its just the wording of the sentence.

Rich