Static and Dropped Calls

[glenng3]

We've had several reports from phone users that they are on a call when they hear static and the call is dropped. This seems to happen when it rains and for a few days after it rains. We have three T1 lines from AT&T connected to our CM 3.1.5 system. (AT&T calls them "DS0" lines.) Looking at CDR, the dropped calls seem to come in on the same T1 (call it 101). We opened a ticket with AT&T. They looked at 101 and at the other two T1s. They said nothing was wrong with 101, but they were seeing a lot of errors from the DSU/CSU on 103. They said if we fixed the DSU/CSU on 103 that the problem on 101 would go away. Does that make any sense? What else should we be looking at? Thanks. -G.

 

[jmbailey]

If your sync source is running off of the CSU/DSU 103, and it is taking lots of errors, then it could impact other spans. However, I would think that if the sync source was causing issues on 101, then AT&T should be seeing those also. Unfortunately, AT&T is always less than helpful (personal experience over many many years). I would suggest trying to correct the CSU/DSU for 103 as AT&T suggests and then if it still happens, throw the ball back in AT&T's court.

 

[glenng3]

We did replace the CSU/DSU on 103 last night and have had no reports of dropped calls. But it hasn't rained for four days. The primary sync source is 101, and secondary is 102. 103 does not provide sync at all. AT&T is scheduled to test 101 and replace the smart jacks this evening, after much complaining from us. I agree with the assessment of AT&T. We are thinking about switching to Time-Warner.

 

[jmbailey]

We use Time Warner for several of our PRIs (local and LD). We actually have 40 PRIs we split between Time Warner and Cincinnati Bell for redundancy purposes (we do 160k calls a day).

Glad AT&T is starting to work with you. Hopefully they will find something sooner rather then later.

 

[wmainc]

No trouble when it's dry, and trouble only when/after it rains? Unless the smart jacks get wet when it rains, I don't see that they could be the problem. The provider never wants to admit to a facility problem because it's all on them to fix it.

 

[ewaaijenberg]

You can do a list meas ds1 sum 1v03 to check if the board has errors. If you have errors you should ask at&t to check again.