Thousands of External Extensions

Hello to all,

I have a question to the experts or to anyone with knowledge to it. What are implications of having a large number of external extensions deployed? I read somewhere that if you gone up 300 internal extension you must setup a kamailio. Does it also applies to external extension as well?

I would suggest that you start off by taking a look at this thread which discusses number of extensions and potential implications:
http://www.freepbx.org/forum/freepbx/users/recommended-maximum-number-of-extensions

The bottom line is that as long as you have sufficient hardware to support it, a larger number of extensions isn’t a problem. What you really have to watch out for is the number of concurrent calls that are running… this is where Asterisk may eventually run into problems. I believe that concurrent call problem starts to come in the 200-300 calls range, but it depends on Asterisk version and a number of other factors. Realistically you shouldn’t have a problem with 300 remote extensions as long as you don’t have 200 of them talking on the phone at the same time…

Bandwidth may also be an important factor depending on where you plan on deploying your server, as you’ll need to make sure you’ve got enough piping into your FPBX to be able to handle however many concurrent calls you want to support.