I have two BT (British Telecommunications) telephone lines, giving me the convenience of two separate numbers. I’ve known for some time that I could achieve greater flexibility at lower cost by using VOIP (Voice Over IP), but changing over was never urgent so I left well alone. That was until this month’s BT bills arrived, featuring a new “payment fee” – an £18.00 annual charge for paying your bill. That’s right, you now pay BT for the privilege of paying. You can avoid the new fee by switching to Direct Debit, but instead I treated it as an incentive to get on with the switch to VOIP. I still need one BT line, for my ADSL connection, but I’ll be scrapping the other and transferring the number to my new provider, Voipfone.

We currently use DECT wireless handsets, so I’ve also purchased a Siemens Gigaset wireless SIP (Session Initiation Protocol) handset and DECT base station, in the hope that I can re-use our existing DECT handsets. The Gigaset is also able to work with an old-style fixed line, so it is ideal for the transition.

Why not Skype? Well, Skype is massively popular and I do use it occasionally, particularly when calling from overseas. Unfortunately it uses a proprietary protocol, whereas SIP is an standard with lots of open source energy behind it, including of course the Asterisk PBX.

It’s going OK. The biggest problem I’ve had is trying to get it working behind ISA Server, Microsoft’s firewall. I’ve had partial success, but only with the X-Lite softphone running on a PC with the ISA Firewall Client installed. I can’t install this client on the Gigaset, so I’ve connected it directly to the ADSL router, bypassing ISA. This is actually a pretty good solution, though if anyone knows how to get this working through ISA I’d be glad to know. Incidentally, call quality is much better on the Gigaset than in X-Lite.

I should save some money, but what’s more important is that VOIP opens up many new possibilities and I’m looking forward to some experimentation.

PS – as chance would have it, Danny Bradbury has a post bemoaning the low quality of some VOIP calls. It’s a fair point, and another good reason to keep at least one POTS (Plain Old Telephone System) line to hand. Still, my experience so far is that the VOIP phone is fine for everyday use. I’ll let you know how it goes.

Technorati tags: voip, voipfone, siemens, gigaset, isa server, dect, adsl, bt