Dropout and Static on Inbound / Outbound Calls

[markatcristorey]

Hi all --

Just wanted to see if anyone had any suggestions on what I should do to troubleshoot this. We've been dealing with an issue for about four months now where off-campus inbound and outbound callers report static and voice dropouts. It's intermittent, and very difficult to reproduce -- sometimes it happens, and sometimes it doesn't. I've done pretty much everything I can think of, save replacing the phone system itself. I recently replaced the PRI card to see if that might do something, and I've tried replacing some cabling, rebooting the phone system and Adtran, and a few other things. I just haven't got any idea what else to do now.

Our telco provides us a fiber to our premises and then uses an Adtran 600 to provide us a voice T1 into the PRI card. They continue to tell us that they don't see any errors or anything on their end, and have done some various fiber tests that they allege to have come up clean.

We don't have the issue with internal calls. I also don't think we have much of a problem hearing people on the other end -- it's them hearing us that's the issue, as far as I can tell. Does anyone have any good suggestions for me? This is getting to be such a pervasive issue that people are beginning to give up and use their cell phones for everything . . . I'm plum out of ideas, and wanted to see if anyone here had any good suggestions.

 

[hawks]

What release software are you running?

 

[markatcristorey]

Oh sorry -- I had put that in the post and while I was editing must've deleted it.

MICS 4.1

 

[markatcristorey]

Just one other quick note -- I have spent a lot of time today trying to nail down the problem specifically, and it never appears to be static -- it's only dropouts. Let's say you have a 60 second phone conversation. There may be 18 dropouts, each one for .25 seconds or so. Enough to disrupt the conversation. Also the dropout always happens to the outbound person, meaning the remote caller hears the dropouts, but the person on-campus never does.

I have a spare KSU but it runs a different software, and so it'll be a bit of work to set it up.

 

[hawks]

Well there were issues with PRI's all the way up to the last maintence release of 6.1. So this problem could be either the carrier or your software. If you can you should go ahead and upgrade to 7.1 that was the last release for the MICS and it had no known issues. Otherwise i think you're going to be in a long fight with your provider pointing the finger at each other. Here is a line from from one of the Nortel Release Notes on the 4.1 and PRI.

Intermittent ‘Not in Service’ & Calls Being Dropped

 

[markatcristorey]

It's something of a recent issue (we had the PRI for about a year without any issues), but perhaps just moving the new KSU is a good move. I don't know offhand what software it runs, but it's probably 5 years newer (ours is from 99) and so it must be 6+.

 

[hawks]

It needs to be the last release of 6.1 I think that was labled MR10. Maybe you will get lucky with it even if it's not the last release, remember not all software had issues but there were enough for Nortel to build fixes within the 4.1, 5.0, 6.0, & 6.1 releases.

 

[markatcristorey]

I just wanted to update this thread with the resolution in case someone comes across this during a search for similar issues.

This one turned out to be a problem on our provider's end, but it took months to get to the bottom of it. Their argument was that when our Internet usage spiked, we'd have a phone drop off. I'd assumed QoS would take care of that, but my response was to bring in a second Internet connection for low-priority, high-bandwidth traffic (streaming sites, etc.). That didn't really do anything, but they kept reiterating the data spike issue. After about a week of completely LIVID phone calls with them, they figured out they had a link-speed negotiation problem on their equipment between their equipment on our site and the fiber network provider they use. Once that got cleared up, everything has worked perfectly since. Turns out it had been dropping a portion of our packets, both phone and data. I wasn't able to tell on my end, since it all seemed to be working reasonably well. We're about two months later now, and there haven't been any complaints, and our Internet speeds have been much more in-line with what we pay for.

As soon as our contract is up with these bozos (2014), we're going to move to a company that isn't functionally incompetent.