I now have a full Voice Over IP setup at home that I am happy with. I will blog technical details later, but I wanted to put something up about what I have.
At the core of the system is a Trixbox virtual machine running on my VMWare VSphere server in the loft. I currently have four handsets connected to this. A Grandstream GXP2000 Enterprise IP Phone upstairs which is connected to a Power Over Ethernet switch, one downstairs (connected via the wireless network) a bog standard analog handset connected to a SIP ATA (more about that in a sec) and a soft phone running on my iPhone (primarily used for testing).
The four handsets are all connected via SIP to the Trixbox server and this allows me to do simple PBX like stuff like dial the upstairs extension from downstairs etc.
Calls get into and exit the system via a SIP ATA (Analogue Terminal Adapter). Specifically a Cisco Small Business Pro SPA3102 Voice Gateway with Router. This is connected to my Virgin Media phone line downstairs and in turn to my wireless router. Calls placed on any handset that are destined for the outside world (i.e. are not a local extension number) are routed by Trixbox to the SIP ATA and out to the ultimate destination. Incoming calls are routed through the SIP ATA to the Trixbox server and on to a ‘ring group’ which simply rings all four handsets.
If the call goes unanswered, it goes to voicemail. These are automatically sent via E-Mail to the wife – she keeps her inbox tidier than me so there is more chance someone will actually listen to it…
The next step is to selectively route some calls over the Internet. I have free calls through Virgin evening and weekends so it makes sense to use them. At other times, I should route them out over an Internet SIP provider that I have an account with. This will lower my call costs and will be subject for a post another day.