Calls getting dropped.

[rmack22138]

Hi all, I have a definity 9.0 prologix on tn2402 processor card.
When I make a call from any station and it goes out a ground start line, the call gets randomly drop always 2 times in a row and then the third time it will go through.

I tested the ground start line and everything is good there.
I don't see any alamrs and I replace the tn747b card and the tn2182c tone card.

What else could be wrong? Thanks inadvance

 

[dufus2506]

Is your CO trunk configured for ground start? And is your system ground secure?

With ground start line, it's more about the CO being able to sense that one leg of the line is connected to ground. It will then start the dial tone.

If the line is setup as loop start, or the PBX chassis has a marginal connection to ground, the CO won't be able to easily sense the connection. Don't count on the ground line in the power supply for your ground connection. You want a proper ground connected to the PBX chassis.

You'll also want to be certain of the Tip and Ring connection. If they're reversed on a CO line configured for ground start, the TN747 card may have trouble connecting ground to the correct leg of the CO line.

Carpe dialem! (Seize the line!)

 

[rmack22138]

Anyone have any thoughts on this

 

[rmack22138]

Yeah I have a good ground on the PBX and when I test the ground start line, manually with a test set, I have no problems.
I have the polarity correct on the tn747b card, If I reverse it, it won't even work.

It seems like to me, when I dial out or use last number redial, if it sends digits to fast, it won't even select a trunk and it just drops out and you have to dial again till it goes through.

 

[dufus2506]

Oooooh... well, that's different.

Slow start of dial tone is common on ground start lines. Especially those with a long wireline distance.

Go to the route pattern you use to send calls to these trunks, and add a pause before dialing. It may take an extra second or two to place a call, but it will become more reliable.

You'd just put the pause in the space for "inserted digits". That will make the PBX wait for a dialtone before sending touch tones to the CO.

Carpe dialem! (Seize the line!)

 

[dufus2506]

Incidently, the best way to do that is to put a "+" or a "!" on the inserted digits spot.

[tt]
0 to 36 digits (0 to 9) Enter the digits you want inserted for routing.
* When * is in the route pattern and the outgoing trunk is signaling type "mf", the MFC tone for the "end-of-digits" is sent out to the CO in place of the *.
# When # is in the route pattern and the outgoing trunk is signaling type "mf", the MFC tone for the "end-of-digits" is sent out to the CO in place of the #.
‘,’ Use 2 places. Creates a 1.5 second pause between digits being sent. Do not use as the first character in the string unless absolutely necessary. Misuse can result in some calls, such as Abbreviated Dialing or Last Number Dialed, not completing.
+ Wait for dial tone up to the Off Premises Tone Detection Timer and then send digits or intercept tone based on Out Pulse Without Tone y/n on the Feature-Related System Parameters screen.
% Start End-to-End Signaling.
! Wait for dial tone without timeout and then send DTMF digits.
& Wait for ANI (used for Russian pulse trunks)
p The associated trunk group must be of type sip. Enter the single digit p for fully qualified E.164 numbers. The p is translated to a + and is prepended to the digit string.[/tt]

Carpe dialem! (Seize the line!)

 

[rmack22138]

which character do I use for pause.

 

[dufus2506]

See above.

Carpe dialem! (Seize the line!)

 

[rmack22138]

Ok I did try the pause ! + but it didn't work.
So I retested the ground start line and you really have to hold the ground to tip for a good second to get dial tone.
But I think the PBX is flashing ground to tip to fast and not able to seize dial tone.

Can I adjust the ground to tip flash timing?

 

[dufus2506]

That sounds more like a CO trunk problem to me.

Is it true on every trunk you have? Just one?

I don't think this is a timer you can set. The flash timer is different than the ground start connection.

If I were you, I'd complain to your Telco provider. It shouldn't take more than a brief touch of ground to start the line dial tone. It may take a second or so to get the dial tone started, but you shouldn't have to connect the ground for very long at all.

Carpe dialem! (Seize the line!)

 

[rmack22138]

Yeah it seems to be happening on all 8 ground start trunks.
This just started happening to, I haven't had a problem at all before.
I did talk to the Verizon and the say they tested the line
and they are all in spec to their standards.

 

[dufus2506]

You might have something bad in a local cable. Specifically, you could have a splice connection full of water or something.

I'd still be complaining to Verizon.

Carpe dialem! (Seize the line!)

 

[rmack22138]

I switched one truck over to loop-start and the problems are gone.
I think I'll switch them all to loop-start.