[asterisk-users] Nortel 81C MSDL Trunking to Asterisk TE110P, Nortel Resetting PRI Channels

[Don Pobanz]

Marlon_Blair at doh.state.fl.us wrote on Tuesday, February 13, 2007 10:17
AM
> We are currently working to trunk from a Nortel 81C to an Asterisk 
> Server 1.4 running on Red Hat Linux.  We have two PRI trunks which 
> work with the exception of the clock slips, which is causing the 
> Nortel to reset the PRIs once a hour.  Thanks for any suggestions.

Assuming that 'clock slips' are the same thing as 'frame slips'....

Where is your primary clock? Do you have an atomic clock supplying
timing to your Nortel system? Does your Nortel get it's clock from the
phone company? Assuming one of these two is the case, and that both T1s
are connected to the Nortel system, Asterisk should derive it's clock
from the Nortel system. 
To do that you would want to set up Zaptel.conf 
span=1,1,0,esf,b8zs
span=2,2,0,esf,b8zs

Asterisk would then use T1 number 1 to set it's internal t1 card clock.
If T1 1 was not available, then it would use T1 2. 

This line from your Nortel system makes me think it is using an external
clock. If this is the case then you must have an atomic clock or some
other 'external' clock source at your location. 

> 	   CLOK EXT

Don Pobanz