We just changed our LD T1 from Centurtel to TEC. all long distance calls are working fine. However Our Modems are not connecting over long distance. they will connect if you slow them way down to like 2400. I did not do this changeover and my work partner is out this week.. Here is some info on how its setup

Switch is G3R

Type trunk pack 767
Robbed bit

B8zs esf

All calls (LD trunk group) over this are fine. Modems and faxes are timing out before connection is made.

Sta sync shows another DS1 that’s a 464 under physical source location for stratum 4 timing

List trace shows no denial events
List events shows no errors being logged against new ds1


Any ideas??

Thanks

Tom

That is because your new service provider is delivering the T1 using VOIP. Analog data transmission is not supported well with IP, if at all. You'll need to insist that TEC provides you with a real T1, not a virtual one.

Just like Ed stated virtual T-1 does not support analog devices very well. Modems, fax machines etc. I have fought this battle many times.

Mike

Is that why they had us change the line coding and framing mode? that the only differance that I can see from our old T1 and this new one.

Old T1
Line coding was ami-zcs
framing mode was d4

Thanks for the input.

run 'list meas ds1 log 01AXX' where 01AXX is the DS1 board.

AMI/D4 is for a Voice T1 at 56KB per channel. ESF/B8ZS is for a T running 64KB per channel.

If a customer wanted a T just for Voice we generally used AMI/D4, if they were going to be pushing data across it we would go with an ESF/B8ZS.

AMI will not support too many zeros in a row (as I recall, the actual number is 16 - which never occurs on a voice circuit but can happen on a data circuit).

However, I don't think that has any bearing on what your problem is. What Ed and Mike said is what's going on. VOIP is cheaper to implement so a lot of carriers go with it. Unfortunately it doesn't do Analog data well (if at all).

We've spoken about this a lot on the board.

Welcome to the Brave New World.

Now go kick some carrier butt.

Sam

Well after being told it was all on my side of things I had to get a little ugly and they have got things working for now. Thanks for the input guys. We shall see how this new fix works.