[asterisk-users] Tired of dropouts and garbled phone calls - where to go next?

[Mike]

On Mon, 28 Oct 2013, Eddie Mikell wrote:

> All,
> The users in our organization are well, quite frankly, sick of phone service that is being provided.  The choppy phone
> calls, and drop outs are detrimental to our sales force.
> 
> I've tried about everything I can think of.  
>
>       Moved the asterisk server from VM machine to dedicated machine
>
>       More than enough bandwidth
>
>       Setting 802.1p = 7
>
>       Set Dedicated voice traffic 35% of bandwidth.
> 
> Not sure what option would be the best
>
>       Put analog lines in the conference room to avoid the dropouts - leave the sip lines in place for day to day use
>
>       Hire a consultant
>
>       Ditch the system and buy a pre-packaged system - RingCentral or some such.
> 
> There are no local asterisk professionals who can help, and we are a little leery of opening up our system to outside
> consultants.
> 
> Anyone else face the above, and finally abandoned Asterisk for a commercial system?  
> 
> We have 167 users.
> I use Grandstream GXP 2100 on the desktop and Polycom ip6000 for the conference rooms.
> 
> Suggestions welcome.
> 
> Best
> 
> Eddie
> --

As stated in previous replies if you haven't already I would certainly try 
to isolate the problem, e.g., are extension to extension calls good, is 
the problem only on outside calls etc.

We are starting our 4th year of VoIP service and have had two seemingly 
similar episodes to yours during that time.  We are on a non-symmetric 
cable connection, 20/4 (I believe).  After a few days of "crappy" audio I 
started looking for some way to characterize/correlate bad audio with 
something I could measure.  I found iperf (http://iperf.sourceforge.net/) 
to be a free and easy starting point, which actually turned out to be all 
I needed.

I simply ran a "server" instance on our "cloud" server roughly 1K miles 
away and a "client" instance locally.  I used the command line swithces 
that forced udp mode.  This allowed me to see jitter and packet loss in 
both directions.  We had terrible packet loss in the outbound direction. 
This didn't show up in normal browsing, emailing etc., kinds of things as 
I suspect TCP retries masked the problem.  With a little persistence with 
the cable company the second tech found a bad "tap" (I believe) outside at 
the cable drop.  Replacing that solved our issue for almost two years.

The next time this happened iperf showed a similar packet loss problem. 
This time it turned out to be "noise in the system" according to the cable 
tech.  He said it could be from any number of sources but a different team 
would be out to hunt it down the next day.  In the mean time he changed 
out our old Moto SB5101 modem for a more modern DOCSIS 3.0 modem.  The 
multiple channel bonding that it offered was much better at punching 
through the noise.  That change alone ended crappy audio as well as packet 
loss as shown by iperf.