[Asterisk-Users] Help - is voip good for in-house calls?

[Peter Svensson]

On Sat, 14 Aug 2004, Wiley E. Siler wrote:

> Greg had a great idea in having you set it up and try it.  In fact, that
> is exactly how I did mine.  I purchase a cheap clone card for $15 and
> used it to test on one POTS line while I tweaked my configuration files
> and got the system validated.  I tested the system with soft phones, one
> Polycom IP 500, and one Grandstream Budgetone 101.  The Budgetone worked
> well and was leagues easier to setup than my Polycom actually.  

Using a pots may not give an accurate picture. It is a source of echos 
which can, when combined with a slight latency introduced in the voip 
links, change an acceptable reverb to a nasty echo.

The cheap clone cards are all of the x100 card I believe. It has a fixed 
impedance of 600 ohms pure resistive. A lot of countries outside USA seem 
to use other line impedances. The mismatch leads to echos.

> For expandability, I believe that the cap I have seen is about 60
> concurrent calls for one Asterisk box and that is with a pretty serious
> server by most users standards.  I cannot imagine having that many calls
> at this point so I am fine but I jus though t you would want to know.
> The nice thing about * is that you can just build another server and
> link them together over IAX. Again, the low cost of implementation pays
> off and you get to continue growth.  I will never go back to proprietary
> PBX now that I finally have a solution that I can control.

With no transcoding you should be able to go higher than that I expect. 
For local ip phones g.711 is probably usable. Most low numbers I have 
seen seemed to do a lot of transcoding to liwer bitrate formats.

Peter