Yesterday, with my friend Younus, since he has one IP phone 
, we tried to play with Trixbox.
Installing the software took about 30 minutes to install the operating system and asterisk and Trixbox.
I was nice time to try to have PBX (Central) and creating different extensions and everybody has his own extension. and once you didn’t answer your extension, we configured the voice mail to answer the call, and later the server will send the voice message to your email which is configured in your extension.
We tried also to login to the same PBX from outside the local network, this is very important, since I’m planing to give my brother Nasser a phone – he is in Australia – and he will configure it to have it logged in my PBX, and later he will be feeling at home and it’s a matter for 2 digits dialing to call my mom, or even if he is planning to talk to one of his friends in Riyadh!!.
I was planing to try asterisk , but because it needs more time to understand it and everything has to be command line. I had putting it delayed and delayed, But TrixBox since it’s WEB based and simplified. you don’t need more than 2 hours to have everything working!!
I ordered 2 IP phones and 1 FXO,FXS extension from VoIPSupply.com to have complete the connectivity and make possible for me to call through the PSTN , the normal connection