Static hissing in outgoing call

[anoop.kr]

Hi,
Our Vicibox is sitting behind an Alcatel exchange, we have created a SIP trunk to the Alcatel EX to make the outgoing and incoming calls to the Vicibox, everything was running OK, but all of a sudden, a loud static hissing sound started to appear on outgoing calls, sometimes it disappears for a few calls and then comes back. Incoming call is perfectly fine. The only change we did is we added two more incoming numbers (Forwarded two numbers to the SIP trunk from Alcatel exchange), anyway we haven''t noticed that right away the change was made. However we reverted everything back to the previously working state but that noise is still there.
Any help to rectify this issue is greatly appreciated.
Our carrier config:
[occTrunk]
type=friend
qualify=yes
host=10.41.12.203
allow=all

Thanks and regards.
Anoop

[carpenox]

Test with another carrier to make sure it's alcatel

[anoop.kr]

Hi,
Unfortunately I cant do that, there is no other provider comes to our premises, and we cant connect it to the actual telco directly as well. We have been testing it for months, there had been many other issues, but this has never occurred. All other issues have been solved, actually we were at the point where we were going to release it to the end user, do you think a re-install might resolve the issue ?

Regards
Anoop

[carpenox]

Is the server local in your office?

[anoop.kr]

Yes, both of them. (Alcatel OXE and Vicidial), but the Alcatel is managed by another department so, it is not easy for us to play with it and we are kinda restricted. In fact all the trunks and etc are created by them only.

[carpenox]

I bet there's a wire, plug, or some sort of light by it that's causing the hissing. Check the path of the cat5 cable follow it the entire way, any wire that crosses over it, take it off, if it goes over a light source, change it's path, etc

Chris

[anoop.kr]

Well, that reminds me of an old failure I attended years back (of course something else), we would spend days and days the failure simply refused to be rectified at last it was a light with a faulty power supply was at fault. Thanks for the direction I will work through this new lead.
Regards

[anoop.kr]

I tested the condition using my phone with a softphone, that connects to a wifi access point first, then through ethernet to a IT network switch then an alcatel router (10.40.X.X to 10.42.X.X) then our server (Vicidial), another eth cable originates from Vici server through a telecom switch go to the Alcatel OXE. In my test condition I omitted all the agents and associated devices, but the problem persists, there is no visible problem in other devices connected in these networks. Can we rule out a codec issue ?
Regards
ANOOP

[anoop.kr]

Hi,
We have a defunct Issabel server in the same host server where our problematic Vicibox resides, we tested with the Issabel server, and it was flawless. That pretty much eliminates the plausible issue of emi rfi , stray power cable etc or a cable at fault in general?
We even tested with a freah installation of Vicibox without any improvement, someone please lend a hand, im out of ideas.
Regards
Anoop

[anoop.kr]

Hi all,
At last, apparently it turned out to be a codec issue, the codec setting at the OXE end was set to auto, we changed it to G711 , and the problem went away, we waited for some days as it was showing OK sometimes and after 4-5 days the problem has not returned so far. So I assume the problem is resolved.
Regards.
Anoop