[asterisk-users] Connecting a Rolm CBX to Asterisk via T1?

[Lee Howard]

Joshua Kinard wrote:
> Another attached text file shows what iaxmodem is doing during all of this.  Something about adjusting skew.
>   
> [2008-02-15 17:11:12] Adjusting skew to -50.
> [2008-02-15 17:11:12] Adjusting skew to -100.
> [2008-02-15 17:11:12] Adjusting skew to -150.
> [2008-02-15 17:11:12] Adjusting skew to -200.
> [2008-02-15 17:11:12] Adjusting skew to -250.

There is no mechanism for iaxmodem to pull clocking right from Asterisk 
other than examining the IAX2 timestamps.  So in the event that iaxmodem 
isn't getting voice frames from Asterisk iaxmodem is left to use 
clocking solely from the system clock... which may likely not be in-sync 
with the T1 clocking... and so iaxmodem the "skew" messages you see is 
an attempt by iaxmodem to compensate for a clock skew between the system 
clock and the timestamps on the IAX2 frames... but because iaxmodem 
isn't getting any voice frames you get a run of these skew messages 
until the call disconnects.


> Added, how does this look?
>
> exten => s,1,Dial(IAX2/iaxmodem0/${EXTEN})
> exten => s,2,Busy
> exten => s,3,Hangup
>   

Better.  :-)

Thanks,

Lee.