sundance-communications.com/forum Forums TDM Business Telephone Systems Inter-Tel Telephones & Systems cs5000 one way audio

If anyone can help out on this problem, it would be greatly appreciated.

I have a customer, with 2 cs 5000 ip phone systems tied together by way of the network and a point to point pri. The pri isn't really used, it just in case the network goes down between the buildings. What is happening is from time to time, an incoming phone call, will only have one way audio. The caller can't hear the person that they called for. The called person can hear the caller.

There seems to be no issues for internal calls or outgoing calls that the customer places. It appears to happen on incoming calls randomly.

The carrier has been out to look at the circuit and can't find anything, lol. The carrier is using a t-span, with sip trunks and internet connections on the span. The carrier separates the internet and voice lines with an adtran total access 904.

Customer is blaming the phone system for the problem. Tech support said to put the one way audio call on hold, pick it up from another phone to see it the problem changes. If it is still one way audio, the carrier is at fault. The one wayprob lem stays no matter what phone you pick the call up at.

The circuit for the system are 2 pris. Calls can come in on any of the spans. I have frozen the system, sent the db and freeze files to tech suppport and they are looking at them. I am tring to get the problem to happen, to caught the problem in the files as it happens. Not 2-3 hours later.

If someone can tell me where to isolate the problem to, it would be a great help!!!

Thank

Mike

What versions are the 5000's?

One way audio in the past for me has been a NAT issue. Do the IP phones connect directly to the phone system over an internal network or external?

Thanks for the replies.

The software version is 2.3.4 I beleive. I'll check on it. The network is an internal network of the complex. fiber connects the buildings. As I said, there hasn't been any issues on outgoing or internal calls. Only on some incoming calls. Weird, not any one phone or set of phones, not a certain pri.

Thanks

Mike

NAT wont be your culprit here on a LAN...Does the one way audio condition only happen on CO calls and not on IC calls? That will be your telling tale. There were some issues on early 2.0 stuff of one way audio but I havent heard of any issues like that since. If it happens on IC calls as well there is some ports being blocked likely. I assume that the network is routed and not flat?

This turned out to be a bad T1 card. Didn't want to just throw parts at it, but this seemed logical.

I must have misunderstood, I thought the T1 card was for backup. BTW, I love your screenname; I replayed that SNL in my head when I saw that. Nicely done.

I must have misunderstood, I thought the T1 card was for backup. BTW, I love your screenname; I replayed that SNL in my head when I saw that. Nicely done.

Thanx on the screen name.

There is a T1 between nodes and a PRI from the telco to each of 2 main nodes. Incoming call alternate between the 2 PRI's. If we were to lose a PRI (it happens) we can get calls via the other. We have a police dept, so we have a lot of redundancy. I wish the 5000 was truly redundant. Maybe someday...