Digium TE410 Quad T1 card system.conf config question

I have two Quad T1 cards in a server - eight T1 ports in total. How do I setup the clock timing for each span considering the timing source? Each span is running as the NT source and to provide timing for the connected T1s. For the first span I have

span=1,0,0,esf,b8zs <= this should provide timing for span 1 T1 line.

What should the following spans be set to? For example span 2:


and so on. Should the first span provide master timing to the other spans? Or do I just put

span=2,0,0,esf,b8zs or ? for each following span?


I assume these are connecting to channel banks or the like ,

the all will be 0 as they are all providing timing to the other end.

you would only set 1 ,2 etc if they were receiving clock from the other end

It’s for a VoIP lab where I’m simulating the PSTN with the eight T1 cards. During the student’s labs, they use Cisco Call Manager Express and Asterisk PBX to connect to the simulated PSTN’s T1 lines. Here’s what one of the 8 networks looks like: http://cmpn-313.wikispaces.com/CMPN-313+Labs


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Thanks Malcom. I’ve switched over the configs as per ianplain’s suggestion and will let it run this weekend to see how it works. It makes sense with the problem that I’ve been seeing. I’m troubleshooting an issue with an Astribank (might of read it on the PBX in a Flash forums) losing sync. The Astribank locks to the first Dahdi device’s clock, the Astribank would lose sync after 4 to 6 hours and the T1 over USB would fail if there were no T1 lines connected. I’m pretty sure that my initial configuration was the fault by not setting the Digium card spans to local clock timing.