3300 T1 Dropping Calls

[Nunavutel]

The issue I have is with a 3300 ICP. This seems to be a strange setup I can find no where else, and I cannot get it working properly.

This 3300 is using T1\D4 trunking, Connected with a T1/E1 framer card installed in the first slot.
What makes this "different" is that it's only "half" of a T1, ie only 12 channels.
It is "different" again than usual, in that it's not using DID services.

There's two trunk groups on the T1, programmed by the Telco with 1 lead number for half of the T1, hunting 6 channels each.

Almost all of the time callers into the system get ringing to dead air, or error tone.
The users, when recieving calls get ringing and when they pick up they either get dial tone or dead air.
Calls coming in get properly answered less than half of the time.

One trunk group's answer point is a Ring Group and the other group goes to a single set, which has multiple appearances or itself.
All are using IP sets.
All outgoing calls are working great.

I've checked the SMDR records and these dropped calls show up as 3 or 4 second calls.

Any ideas? What have we missed?

 

[Supernova99]

You will still need to program all 24 channels regardless of the fact that the telco is only providing 12, and just not add them to the outgoing trunk groups

You might find that the incoming calls are being presented on channels that are not programmed



Share what you know - Learn what you don't

 

[Nunavutel]

If calls came in on un-programmed channels, how would the correct sets be ringing?

 

[bobcheese]

You know, I have seen something like this before. I worked on a support desks and one of our tech's had installed a 3300 on PRI with 8 channels but for some reason they could only get calls in on Channel 1. When I connected I found that trunks had the wrong trunk service (and COS) settings. Once I changed these all was fine. Is this a new install or an existing site that has developed a fault?

 

[Supernova99]

you misundertood me you are saying

Almost all of the time callers into the system get ringing to dead air, or error tone.
The users, when recieving calls get ringing and when they pick up they either get dial tone or dead air.
Calls coming in get properly answered less than half of the time.

So the telco maybe trying to present calls to channels that are not programmed. If you just program these as normal so that all channels are live you might rectify the issue.

Share what you know - Learn what you don't

 

[Nunavutel]

First of all, Thanks you for your responses and knowledge.

Supernova99; The telco has confirmed that only the first 12 channels are programmed, the other 12 are turned off in the Switch (DMS-10) and in the Span (an HDSL transport medium).

Bobcheese, glad to hear someone has a similar problem.... unfortunately, looking at the SMDR; when calls do come in properly they arrive on random channels of the T1. All of which work (at random) for incoming, and ALWAYS on outgoing.

The company I work for has many setups working properly, which are almost the same setup.
The only Glaring difference is that this site is not using DID service.
Simply 2 phone numbers, which point to 6 channels each on the T1.
From what I can tell the only difference is that we program "Answer Points" for the trunk groups. And therefore cannot input any DID (insert\absorb) info underneath.

It's almost as if the 3300 is sending a signal out to the DMS when the phone is picked up, sometimes. And when the Auto Attendant answers, usually. What ever this signal is, the DMS thinks it's a Disconnect.

Thanks again.

 

[Nunavutel]

Wow, So this might be a new one.

We ended up having the Telco send digits after the wink.
We simply programmed the descriptor to Absorb those 4 digits and we inserted the answer point. Huzah! it works no problem.

We had to change some things in the Re-Route form for Day\Night1\2 service and we're working like we're hoping.

I'm calling this type of service "Faux-DID" or "Uni-DID",
I cannot decide.

Thanks again for the ideas, they kept me sane with something else to look at, keeping hope alive.

 

[dryaquaman]

I've got a nagging feeling that I've seen this one before
Been trying to put my finger on it but it's been a bit too long since I've had to mess with it or which site it was on.

It seems to me, it had something to do with "meter pulses".
Check the SMDR options and be sure that anything to do with meter pulses is turned off and retest it.

Dry Aquaman

http://www.university-music-on-hold.com

 

[BrianWarner]

You didn't need to have telco send digits. You should have set your incoming start type to "Immediate" and all would have worked. You don't need to program all trunks on a fractional T-1. If you do trunks 13-24 could possibly show out of service and raise an alarm.

 

[BrianWarner]

I should have added that this type of service is called "Trunk Associated Service". A very common thing here in the heartland.