Patton 4112 PSTN Gateway Echo Issue

[running]

Here is the setup
6 GXP2110 .108 firmware
1 Patton 4112 PSTN Gateway tried 3 different firmware, running the recommended one by 3CX at the moment
3CX 10 SP4

Network Setup:

Main Switch connected to most of the IP phones, IP PBX is connected to a switch off the main switch, the Patton is also on the same switch the IP PBX is on. There is also a sonicwall router however we are not going outside of the network for VoIP Calls so I don't see how that would contribute to the echo we are getting.

I've tried changing gain levels and every echo setting in the Patton with little result. I also plugged a regular phone into the line we are using and there is no echo on that. Extension to extension is fine, I also tried a VoIP call with my nexvortex account and there was no echo. I did also try a SPA303g, same exact results. I would go all VoIP however they have DSL so i'd be concerned about upstream bandwidth. I will attach 3CX logs and wireshark trace, i'm really stuck on this one though.


Links to 3CX Logs and Wireshark

http://db.tt/SL2d3SkY

 

[leejor]

Which direction experiences the echo, both?

Sometime the type (capacitance, distance from a central office) can have a detrimental effect. Conditionss you may not be able to completely compensate for. Remember to look at echo as audio being fed back to you with a slight delay. The end experiencing the echo is sending a level higher than the far end can deal with and some is leaking back. So the lower the transmit level, the less chance of echo. If it weren't for the delay, there would be no issue as it would not be noticeable above the normal side-tone. The delay can be the result of distance (satellite calls are especially bad) or, in the case of VoIP, the digital to analogue, to digital conversion process.

 

[running]

Yeah, echo on the 3cx side is worse though. Also im getting reports that if 2 people are on the line they can hear each other

 

[leejor]

Yeah, echo on the 3cx side is worse though. Also im getting reports that if 2 people are on the line they can hear each other

Assuming that you don't have faulty gateway,( and there is the possibility that you might), the only way to be sure is to swap it for another... you may have some induction issues in the cable pairs from your phone company. If you are in an office building then it may be a riser pair problem, that is, the cable pair from the demarcation in the basement (usually) up to your office. I'm also assuming that these conversations, the ones with crosstalk, are using two different trunks on the gateway.

 

[running]

Yea 2 separate trunks on the patton. They had been using an old analog PBX without this issue, however i'm plugged into 2 wall jacks while the old PBX was plugged in where the main feed gets split off via a punch down block. Does not make sense though when I plug a regular phone into the wall it works with 0 echo. Maybe I'll get a new unit

 

[leejor]

While it should not normally make a difference how you plug into the phone line. It would not be the first time that there have been wiring issues. If practical, you could try re-connecting the gateway as close to the demarc block as possible, using new wiring.

 

[running]

Ok, I should be able to just bypass the punch down block and terminate it right into the patton right?

 

[leejor]

Yes you should be able to, as long as you have the proper connectors, there should be no problem. Crosstalk, in office buildings is sometimes the result of installers being short of pairs and stealing the tip and ring from other pairs to make a good one on the riser pairs, or incorrect termination at one end or the other when the cable was installed.. If you were to use the tip from one pair and the tip from a second (because there was a short or ground on the ring side of both pairs, then the run would not be twisted. That can introduce crosstalk from other pairs.

On your gateway you should also check any impedance settings. Sometimes the default is not the best for your particular install.

 

[running]

So we managed to get the echo to go away by tweaking settings in the Patton, now all we have left is the issue when someone gets on another line, they can hear each other, almost like they are trying to use the same line to talk. Anyone had thoughts? The wiring we checked out and is fine.

 

[leejor]

Try to see if you can narrow it down to specific trunks. Maybe it is happening on all of them (then I would suspect the gateway), but, if you can run some tests after hours and find that it is happening on two particular trunks then you can try swapping cable pairs around to see if the problem stays with the specific ports on the gateway or follows the cable pairs. If it follows the cable pairs then you need to re-check the inside wiring or pass it on to your telephone provider.

There is always a possibility of a faulty gateway too.

 

[bkranson]

I had a similar issue in my office. We were using flat 4 wire cables with RJ-11 connectors. There were 6 cables all less than 6 feet long going to two Patton 4114 devices. Once I replaced these 6 cables with Cat5 twisted pair (I cut off two of the pairs at the connector) and put on RJ-11 connectors, the problem went away.

 

[executek]

I'm having an issue with the echo as well. I tried adjusting the Rx and Tx decibels but no success.

Would you mind sharing the tweaking from your Patton device?