sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Call Logging and Channel Banks

Hi everyone, I recently installed a call logging solution at an outgoing call center that taps off of six 24 channel Premisys Slimline FXS units. The loggers are 16 channel USB models and they feed into 3 servers. The T1 lines are ground start.

On the dialing end, I have dial pads for manual dialing that are connected to PC modems which are used for automatic dialing via interviewing software.

When these loggers are attached, I am having a problem where certain lines can not dial out. Initially, there was a problem with the volume gain on the logger units being set too high. Turning this down solved that for some but not for all lines. We are still having issues with other lines even with this gain turned all the way down.

I've tested the voltage of these lines with and without the loggers attached. Most readings come in at around 21.2 on-hook and 5.0 off-hook but one out of every ten fluctuates wildly.

Does this mean anything to anybody? I'm having trouble finding anyone interested in helping me solve this. The logger company says to replace the logger but I don't think that is it. The troubled lines don't share a common logger. The phone tech side is that the dialing worked before the loggers were introduced. I thought I'd just throw this out here to see if anyone had anything off the top of their head.


I am not a phone professional and have been trying to learn some phone basics to figure this out. Would wildly fluctuating voltage create problems dialing where some go through but others don't? Is it line noise or a volume issue that causes a dialing issue? Or is it all voltage?

FYI. T1's are not ground or loop start. They contain a total of 24 64kb/s channels that are translated ground or loop start if the T1 is "channelized". If the T1 is not channelized it is considered a 1.544 Mb/s "pipe".