atcomsystems.ca/forum Forums TDM Business Telephone Systems Comdial Telephones & Systems Comdial DX120 PRI, dead air calls

I have a Comdial DX120 installed with a full PRI.
The DX120 is running software version F20 and the PRI chip is GO5.
When a DID is called from a land line or cell phone the call just sits there in silence. You will never be connected, hear a ring, a busy, or reorder tone. I have stayed on the line as long as 5 minutes and did not ever hear anything,
This happens about every 25 calls, not all calls.
It can be duplicated.

This happens when a CSU is being used or just a direct connection to the DX120 which does not need one.

I have set up a telephone to have all 23 channels appear on buttons and when the dead air call happens I do not see a line appearance like a normal call. The carrier tested with me to each individual channel and was able to duplicate the problem. They said by setting up a D-channel trap they see the dead air call being acknowledged by the CPE equipment but there is not a line appearance or even a quick blink to let me know there is a call.
The carrier says it is not their problem.

PRI card and KSU have been changed out.

Please help,

Mike

I have a customer that called me on Thursday with the same problem. DX-120, dual cab, PRI and I was abble to dup the problem. Getting ready to open a ticket with Vertical. Anyone have any ideas? You know what Vertical's gonna say, COLD START THE SYSTEM.....

First of all, if this is a PRI coming right from the smart jack or NIU, then the CSU is required, no question. That being said, since you were able to duplicate the problem with and without the CSU, that is really secondary (but still important, especially once you get Vertical involved).

Have you gone thru and double-checked all items in C.O. Line Application? That's probably where Vertical will start, by verifying correct programming in there. Also, verify you're not using Answering Position if using D.I.D.

Please keep us posted, but keep in mind that if it gets too technical, we'll probably have to move this thread into the Installer forum.

Justin

Precise, what cabinet software and what firmware on the PRI?

Thanks for information on CSU's?
Mike,
Thanks for getting back with me the other day. I will be going out to my site on Thursday. I have worked with Vert over the phone for about an hour and the ticket is still open. On Thursday 2-21-08 we will find out what the issue is and I will get back with you. 10 to 1, bad PRI card. They say if I program keys for all channels and they do not light upon incoming calls, its a telco problem. Your telco says its a D channel problem. Vert says if its a D channel problem then all calls will drop. Sometimes I think a higher power does not want me sitting at my desk playing party poker all day.
Jim

Since this was originally telecomtech1's thread, I'll go back to the original post first: any update on this?

Now, on to the tag-along Jim, any update on progress?

Thanks!

Justin

This morning the new loop and circuit was cutover by AT&T/Verizon for the T1/PRI with the dead air issues.

I set up a phone with appearance for all 23 channels
and Verizon tested good to all of them. We then proceeded to call in about 15 calls near the same time and did not have any failure.

5 years and counting: I did ask Verizon if they could emulate a 5ESS setting and they would check into it.(They are using NI2 Northern Telecom DMS 100)

I did put some ferrite cores on my KSU cables.

I will keep you updated as a few days pass for real live customer testing.

Mike

This is whats going on here. I got on site today for the first time due to ice storm that came in on Thursday and Friday. After programing all 23 trunks on line keys I was able to dup the problem about every tenth call with no light on the incoming trunk. I was able to press trunk 1 and answer myself even though it did not ring or light up. Worked with Vertical tech suport and we are going to upgrade the switch from F19 to F20, the PRI firmware from F05 to G05 and add the dx-80 hex file to the voice mail. All file have been downloaded and once the firmware gets here I will find out if this is the fix. I have been in direct contact with Mike and it sounds like his troubles are gone. NuVox is our local on this project and they say its not them and they have done a ton of testing. I will get back after the upgrades that will take place next week.

Here is the latest update on the dead air issue with the Comdial DX120.

The T1/PRI circuit has been replaced with a new loop from AT&T, a new smart jack and new cable pairs. Verizon has also replaced their circuit.

This was all cutover on Sunday and 2 days later I still have the same problem today.

The customer is talking about getting another telephone system if I do not have a solution.

I will be contacting Vertical/Comdial 1st thing tommorrow morning about the same problem again.
Wish me luck!

The following is pasted from an email from the carrier:

Good Afternoon Mike,

I received your report callers are getting the same dead-air issues. Everything is new on the network side so the only common denominator is your internal wiring and equipment. VerizonBusiness is willing to pull D-channel captures on completed and failed calls for your hardware provider to compare. VZB also recommends you set up default routing in your switch so any unrecognizable digits will still complete.


________________________________
The following e-mail for this Ticket was received on 2/26/2008 3:27:02 PM
verizonbusiness.com)


Everything is new on our side. We can pull two D-channel captures and email them to you if you can reproduce the dead-air.
--------------------------
Verizon Business
Local Voice/Voip MGR

Any response is appreciated as I see one other tech is having the same problem in another state.

Thank you,
Mike

My software and firmware upgrade is taking place Friday 3-7-08. I will keep Mike posted if this resolves my issues. It was my understanding Mike was going to have a conf call with the telco and vertical, but I have not heard from him in a couple days.