Need assistance with Echo, Buzz, Dropped Calls, poor quality


My name is Joe Lourenco and I work for C & C Technologies, currently on assignment in Brazil. My predecessor installed Elastix Asterisk, and did the config via the GUI. We are running a HP server with an E1 card. No other services run on this server. Our phone provider is Embratel, and my predecessor made an effort to move onto OI. TIM is also in Brazil, but I am not familiar with quality of any of them. FYI, unfortunately, phone and internet service in brazil is still precarious because, 1. still developing, and 2. people steal the copper cables, and other nonsense. Anyway , I am having huge problems with the Quality of Service in the phone calls (VoIP). International phone calls are dropping, and when they go through, ECHO begins with Buzzing that both parties can’t hear each other correctly at all. Restarting the server helps, but only temporarily.

We are currently working on rebuilding our systems to use full asterisk, without Elastix. However, for the time being, what could be causing the problem? The card? Any misconfiguration somewhere? Anyone experience this type of problem? Or is it the phone company? Any suggestions to begin with would be a great starting point.


Joe Lourenco

Joe, I lost lots of my remaining hair over the last couple days figuring out that my call quality issues such as crackling, popping, and clicks were as a result of not enough bandwidth. So in your case it could very well be the lines.

If you’ve a decent internet connection on the box perhaps you can buy a incoming DID and test to see if similar issues occur using a SIP or IAX2 trunk. In my case the IAX2 trunk worked better in the limited bandwidth situation.

Sorry I can’t help further. all the best.

First thing first.

Joe, you should first analyze different parameters. Afterward the solution will be much easier… There are several tools that will help you do so. One that I am familiar with is PBXMate from SoliCall When analyzing, you need to pay attention to the following indicators:

  1. Packet Loss - indication for number of audio packets you lost.
  2. Jitter - yet another important factor for network quality .
  3. Delay - a long delay might cause bad audio quality (especially acoustic echo).

Please report your findings.