[Asterisk-Users] Asterisk - fax - spandsp

[Michael Welter]

> What is in the bug tracker helps make things clearer to people who know 
> what they are doing. What we need is something that makes things clear 
> to laymen. Saying internally and externally clocked doesn't cut it. It 
> needs to be made clear to laymen that clocking internally is rarely 
> right; that slaving to a PBX, when there is also a PSTN connection is 
> almost never right; that the PSTN is the grand master of the telecoms 
> universe, and all Asterisk boxes should be its slave.
>

Maybe the confusion is because some pieces of the explanation are being 
left out.  If you look at the leads on a synchronous RS232 interface it 
is very clear:  Rx clock and Tx clock, and people understand that.  It's 
not as clear-cut with T1/E1.

I'm not the person to explain this, but someone (Rich Adamson perhaps, 
or a Digium engineer) needs to explain phase-locked loops and the 
recovery of the timing signal from the data stream.  Perhaps 
understanding that the timing comes from the data stream itself might 
lead to better understanding.