When I mention to someone that I have a PABX at home, people always ask me – WHY???
Early Media – this is a fancy way of saying that when someone calls me it doesn’t just go “ring ring” – I have it going “rrrrrinngggggg rrrrrrinnnngggg” like an old-school telephone. I’ve considered having cackling monkeys, but I don’t want to confuse people too much.
Free Calls Home – Anywhere I have full Internet access (like at an Internode CityLan hotspot ;) I can connect to the PABX and call the “extension” that rings my home phone. End result, free calls.
Call Announcements – I [can] have announcements for how much a call will cost, or minutely beeps to remind you that you’re on a timed call. Great for keeping the bills down!
Simultaneous Ring – Calling my mobile phone, in hours that I’ve decided I’m likely to be at my desk at work, will actually ring my mobile and my desk phone. Whichever I pick up first, ‘gets’ the call. End result, cheaper (or in this case, free) calls, without having to call multiple numbers by hand.
Automated Outbound Calls – If I can’t get hold of Missy (my darling wife who has had to put up with all this tinkering ;), I can have the phone system repeatedly call the home phone until it’s picked up. (Say, every 15 minutes). Once answered, it will play a pre-recorded message (eg. I’m running late and my mobile phone battery is about to die).
Direct Peering – Some friends of ours don’t have VoIP, but do have a VoIP-capable ATA. So, we’ve hooked them in to our PABX much like they normally would a fully-fledged VoIP provider. A quick “calls to this prefix go via VoIP” dialplan later, and we can have free calls between our house phones. This is particularly awesome when using the Siemens C470IP Gigaset that we have – it can do multiple SIP providers, using dialplans to choose which to send a call through.
Calling Card Functionality – I can configure my phone to accept incoming calls from certain numbers, and do different things with them. An example of that, is placing incoming calls from a family member into a part of the PABX that allows outbound calls. End result, a family member makes a local call to me, then can take advantage of the good international call rates I get by using VoIP – without all the hassle with ADSL and ATAs. A variation of this would be to put “normal” outbound calls through a PIN checker, so you could isolate users within your house (and allow through family and emergency numbers directly).
External Notification – I have certain calls also have other events attached – eg., I get sent an email, IM, and SMS if anyone calls 000. No, I don’t rely on my cordless phone, VoIP, and PABX for all emergency calls. We have a corded handset by a spare phone jack for “just in case”.
But the #1 reason…
Because I can – I’m a giant bloody geek, with a server and a DSL connection. What do you expect? :)