[Asterisk-Users] T1 Sync clarification

[Steve Underwood]

Stephen Davies wrote:

>On Wed, 14 Jan 2004, TC wrote:
>
>  
>
>>What are the practical effects with in-correct clock sync
>>-like to you hear odd buzzing, or dropped voice or gaps of audio ??
>>    
>>
>
>Old-fart anecdote about this - in the early 80s we had some 1200bps
>modems that we used to connect to client sites.  When our phone
>company went digital we suddenly started getting a } character at a
>regular interval of 10 or 15 seconds.
>
>This turned out to be clock slips in the new digital trunk between the
>two exchanges.
>
>So there is one effect of clock slips.
>
>Steve
>  
>
That must have been an FSK modem. Most advanced modems completely loose 
sync on the first sample slip. The sample slip causes a jump in phase, 
and phase is critical to the correct operation of most modems.

Regards,
Steve