As you might guess from the name, Business Broadband Voice ("BBV") is a Voice-over-IP (VoIP) service that lets you make phone calls over a broadband connection. It's BT's foray into the world of public service IP telephony, and is aimed squarely at modestly sized businesses that want to expand their phone provision.
The prerequisite for BBV is a BT Business phone line and a broadband service. Because the equipment links into the network via an Ethernet adaptor, you'll also need Ethernet connectivity into your broadband service. If you use an ADSL modem, you'll therefore need to get yourself a router that allows you to present the connection to you via Ethernet but at sixty quid or so for a decent brand such as NetGear, this is no great problem.
When you sign up for the service, BT will send you a "telephone adaptor". It's a grey box the size of the average modem, which connects to the LAN via a standard Ethernet cable. You connect a PC into the second Ethernet port in order to configure it (it has an on-board DHCP server which allocates an IP address to your PC so the setup routine can talk to the adaptor) and there are two sockets into which you plug standard telephone handsets (as they're RJ-11 connectors, you're provided with BT-to-RJ-11 dongles). Finally, there's a standard analogue socket that you can connect into a standard land-line socket, which the adaptor can use to make calls in the event that your broadband connection is broken.
Most users will be able to follow the Quick Start procedure to get connected. You run the setup program on the PC, which bounces you to the BT website where you enter the authentication details emailed to you as part of the sign-up process. Once it's done this, the setup routine tells the adaptor how to connect to the world, and configuration is complete. If, like me, you have a static IP address range on your broadband link and the adaptor is unable to DHCP-acquire its IP settings, there's a little bit of manual work to do. This is simply a case of pointing a web browser at the adaptor and telling it the right IP address, network mask and default gateway a two-minute job via a simple GUI. The fiddly thing is that you have to set it by hand before you try to run the setup program (the setup program actually just bounces you to the BT website, where you type in your ID and password, and then it downloads a widget that then communicates with the BT box and puts the right settings in - so if it can't connect to the Internet in the first place, you'll get nowhere).
Although there's a Quick Start guide for people with dynamic addressing, there's nothing for users with static IP addresses. BT might like to consider producing one for the latter group.
Once the service is set up, the green "BBV" light on the adaptor stops flashing and shines steadily at which point you should be able to pick up the phone handset and hear a dialtone (which, for some strange reason, is much more high-pitched than your average landline). From this point on, your phone works just like a phone except that your end of the call is going out over the Internet.
We subjected our installation to a fairly standard test gasbagging with my sister for a couple of hours with her under strict instructions to tell me when the quality degraded. During this time I both downloaded and uploaded huge files to and from a number of remote sites, and there were (to my utter amazement) no drop-outs at all in the voice communication. The only minor degradation we did experience was when sending files upstream on the ADSL line at full tilt, but this manifested itself simply by the normal background ambience in quiet periods between words being replaced with absolute silence. To lose absolutely no speech in a two-hour conversation, whilst deliberately trying to break the service by saturating the line, was really very impressive. Since then, I've used the phone as my standard, day-to-day, phone and have had many conversations at different times of day: not once have I notied any diminuation in call quality.
So what does the service cost? There's a connection fee of £40, and a rental fee of £5 per month per port (there are two ports on the adaptor, so you can run up to two phones). Each line is allocated its own phone number with an 05 prefix. Call charges are similar to BT's Business Plan Lite analogue service, so local/national calls are 3.5p per minute (with a 10p cap for calls lasting less than an hour) and calls to mobiles are 10p per minute (with a 25p cap for sub-one-hour calls). BT 1571 (the voicemail service) is included as standard, though you can turn it off if you wish, and there's no charge for additional services such as caller ID or call forwarding (though obviously there may be call charges to pay for forwarding, conferencing and the like).
Our experience with BBV, then, was entirely positive. The price is right, the equipment worked first time, we were up and running with little difficulty despite having to cater for our static-IP broadband connection, and the communication quality is excellent. Frankly, any business with a basic phone service that's thinking of renting an extra analogue line or two should sign up for BBV instead.
Because you need a BT business line to start with, this clearly isn't for someone who just wants one line. For extra lines, though, this should be the first product you look for.