Echo Question

[pakman]

3300 CXi release level 6.0SP1

I have a site with Echo that's intermittent and have had the CO change out some equipment to no luck. I've ran the internal diagnostics on the PBX and made the suggested changes and no luck. I did stumble on the following and was hoping this would help narrow my search. If the user who's having echo issues puts the caller on hold then picks them back up the echo is gone. One of the hardest things to track down is if the PBX or phone lines are causing the issue.

any thoughts?

Thanks,

[jrg0852]

Very important question. Are these digital (PRI) or analog (POTS) lines?

[pakman]

neither really, there from a cable company so I believe there converted from Coax. They run them through a box that is in the Dmarc then from there they plug into a regular 66 block and I Cross connect them from there.

[jrg0852]

Are they clean with your butt set?

[johnkeri]

Seen that before.
In CO Trunk Circuit Descriptors:
change Balance to 600 and category Short.

The loop is to short, only a few feet.
National Complex works for most loops, but for IP converters.
If you prefer, run the LS measure test.

[pakman]

To answer Jrg0852: yes, they are clean when tested with the butt set.

To answer johnkeri: I have run that test before and have tried the settings with no luck. Now I don't recall what those were as it was sometime ago. I will try this out in the CO form I have Loop and Ground which one do I make the change on or both? I'm assuming just on Loop as in the Analog trunk form the card type is "Hybrid 4 ONS 6 LS"

Thanks,

[johnkeri]

The impedance depends on the loop. Once you migrate an LS trunk to VoIP equipment the loop is virtually zero length.
In default all trunks terminate on 600 Ohm/AC.
Had to change this on 200 and 3300 ICP. Did the test once, just for the hell of it.

The card type makes no difference.