Severe echo on FXO port only

[Mango]

Suddenly, I hear a severe echo, only on POTS calls.  This happens on an incoming or outgoing call, and also if I press # to hear a POTS dial tone.  The user on the other end reports they can "barely hear" me.

I swapped out all the equipment and cables, including the OBi itself, reset the OBi to factory defaults, and upgraded its firmware, but that did not solve the problem.

Connecting my phone directly to the POTS line "solves" the problem.

If anyone has any advice for me I would appreciate it.

Thanks,
Mango.

[Shale]

I would try the different Line phone port impedences.

[QBZappy]

@Mango

Modem is sensitive to jitter buffer adjustments during a call. Your OBi can detect FAX tone and will switch off jitter buffer adjustment when FAX is detected (it might even switch to T.38/FAX Relay if the call peer also supports it). That makes your FAX work better.

However there is no Modem signal detection support.
There is a new feature in the latest firmware (3.0.1.4109) that may help (do a f/w upgrade first).
It allows you to disable jitter buffer adjustment for the next outgoing call, by dialing a *code (of your choice). This is what you can do: Add a Star Code (under Star Code Profile) like this:

*01, Modem Call, set($Noji1,200),set($Noec1,1),set($Cdm1,3)

The 3 set() commands tell the obi to do the following for the next outbound call:
1. Disable Jitter Buffer Adjustment, and use a fixed jitter buffer length of 200 ms
2. Disable Echo Canceller
3. Use only G711u and G711a codec

Replace *01 with any code you like, as long as it does not conflict with other codes.
Then dial the target number and see if the modem call works better.
Note that this only controls the OBi; the quality will still be affected by the behavior of the call peer and any network impairment. Good luck.

We have made reference to this post in the past. Have you at any time played around with above mentioned settings? Note especially the "Echo Canceller".

[Mango]

I have not.  I believe those settings are specific to OBi2/OBi3.