Customer has a Nortel 824 DR5 DS. Here is the issue, a call comes in, they put it on hold, they call an extension or page and the call cuts off. This is sporadic. Also, we troubleshooted the system and the issue follows the lines. We double checked the Disconnect timer with the carrier and all is well. These lines are behind a 5ESS system. What could be wrong here?
I've seen this exact thing with a DR5. It turned out that for some reason, the CO line voltage was above 85 volts. When a call was held, this would overheat the hold bridge circuitry and cause the call to drop. Have you measured the line voltage?
Ditto ^^
We have had similar problems with systems other than Nortel when loop is in the 40 to 60ma range.
Get some specs on the line in question and see if they are out of whack.
Here are the readings that I took from the 2 lines:
Line1 Line2
On-Hook DCV 51.2 42.7
Off-Hook DCV 6.11 5.97
On-Hook ACV .4 .4
AC Ring Voltage 106 97.9
First, are these the correct measurements that I needed to take? Also, according to the Telephone Line Diagnostic Table from Mike Sandman, these readings are within spec.
Did you measure the loop current?
That's quite a difference in on hook line voltage. The loop current is really critical. Are you sure both lines are cutting off? I would suspect a high joint on the second line with that much difference in voltage.
No I didn't measure the loop current. They have had both lines 1 and 2 to disconnect. At this point only line 1 is disconnecting intermittently. Is it correct that the loop current should be from 23 to 35ma?
23 is optimum. Much over 33 is getting too high.