[Asterisk-Users] The maximum capacity of MeetMe

[John Chester]

At 12:58 PM 4/5/2004 -0500, Steven Sokol wrote:
> > I regret that I've only used MeetMe a few times, and only up to two users.
> >
> > Perhaps others that are using MeetMe could comment on the number of
> > concurrent conferences and total users they have asterisk running with.
> > The
> > specs of the systems involved would be most helpful.
> >
>
>I have set up a conference with four people on a very low-end box.  The
>voice quality was very good.  All four were connected using VoIP.  Three
>were using IAX2 clients, and one was using a SIP hardphone.  I suspect the
>system could have easily scaled much further -- the CPU and memory usage
>were fairly low.

I've pushed a low-end system far enough to encounter problems.  I set up 
what I thought was a prototype system on a box salvaged from the junkheap, 
and it immediately became so popular it got overloaded.

* 1, New Jersey:
         P-II 350, 192 MB RAM, RedHat 8.0, * 1.0 stable
* 2, Jamaica:
         P-III 800, 256 MB RAM, RedHat 8.0, * 1.0 stable

7 party conference on * 1 in New Jersey.  3 extensions on * 2 via IAX trunk 
to * 1 (no jitter buffer).  Four calls on * 1: 1 IAX to VoicePulse, 1 local 
SIP, 2 remote SIP on Xten softphones in Vermont and UK.  All calls are GSM 
(including IAX trunk) except for 1 local SIP user who is ulaw.

7 users sounds OK *if* the network connection to Jamaica is in really good 
shape -- but audio quality on the Jamaica trunk goes downhill really fast 
as network quality deteriorates.  It's *much* more sensitive to network 
quality than a regular call across the same trunk -- and it becomes more 
sensitive to network quality as the number of users in the conference 
increases.  On one occasion, a 7-party conference ended because audio 
quality from Jamaica was unusable.  I then immediately called one of the 
extensions in Jamaica, and audio quality was OK.  CPU usage during the 
7-party conference was usually 10 to 15%, with occasional peaks at 50%.

On a good day, the network path from NJ to Jamaica is about 170 msec with 
15 msec jitter (sounds perfect); on a bad day, it's 10% packet loss and 500 
msec jitter.  Needless to say, the latter condition is always unusable.  A 
one-to-one call is still usable with packet loss of 3 to 4% and 60 to 70 
msec jitter (although it certainly has audible dropouts), but a 7-party 
conference sounds really dreadful.