[Asterisk-Users] T1 Sync clarification

[Rich Adamson]

> > What are the practical effects with in-correct clock sync
> > -like to you hear odd buzzing, or dropped voice or gaps of audio ??
> 
> You may get gaps where frames are discarded, this will be across all timeslots 
> so an individual loss isnt a lot of data, you'll probably get away with the odd 
> one but if you get too many and the T1 realigns it could restart and you could 
> see the whole T1 go down and up..
> 
> Not sure how this works in the US with such diversity available but in the UK 
> telcos generally derive sync from another one so most of them are on the same 
> clock source..

It's the same in the US, however in the US there are far more independent
telcos (example, Iowa had the distinction of the most independent telcos 
at 600+ of all states) and many of those do not have an engineering staff 
nor the expertise to address this. Their engineering is typically farmed 
out to either the central office switch vendor or to independent engineering 
firm(s) when needed. Those groups should have addressed it, but in at least 
some cases it was not. 

The US also has some carriers that got into the national and/or international
long distance business with a low budget staff that ran hard but never
documented anything. (I've done some consulting work for two of those and
wouldn't bet a dollar on their attention to detail.)

Rich