H VOIP - Voice over IP

VOIP - General Principles - in VERY simple terms

Your voice is converted to internet data packets which are transmitted to a telephone exchange where it is converted back to audio and can be routed to any phone in the world. 

It needs to know who you are and it does that by requiring you to log into a central sip server (What does sip stand for? Anybody? Thanks Jim, http://en.wikipedia.org/wiki/Session_Initiation_Protocol)

As it is internet based it should not matter where in the world you are so long as you have a stable Broadband connection. But don't use it in America to ring an American number thinking that is free/cheap. It will still think you are in the UK and charge you at international rates! It is, however, a very useful tool for making cheap calls whilst abroad to family & friends back home. This is exactly how companies such as SKYPE can offer cheap international calls.

Broadband Talk

This should work anywhere that you have a WiFi connection to the internet and carries your homehub number with you. It does NOT need to be a BT WiFi connection. The call charges are exactly the same as they would be from your home hub phone at home BUT double check that your calls are using VOIP and not mobile access. In fact, when abroad kill your GPRS and consider killing your mobile phone access (comms manager?)

A word of warning. Many BBTalk/Homehub numbers are in the 05 range. Calls to that range are NOT free. 
If using BBTalk (HTC VOIP or softphone) to dial out you are better off ringing a standard UK landline rather than an 0560 BBTalk number

Having Problems?

You must have a BBTalk number - see the BT Web site
It has to be enabled by BT by entering the info on a server.

To start up VOIP it logs into a BT SIP server. My phone seems to have a problem with intermittent availability even when I have a stable Wifi/broadband connection. I wonder if they need to upgrade their servers? To reconnect I find the only way for me is to disconnect & reconnect wifi until the VOIP finally registers. (Does anyone have any better methods?)

The HTC has to be able to read the SIM on boot up which means the SIM has to be in the phone, enabled (for normal phone and GPRS servce) and set up with the standard BTMobile settings.
If your HTC failed at any of the 4 steps of the config then VOIP will not work

Check your phone is set up for BBTalk by  Start > Settings >Phone > Call Options. You should see your BBTalk phone number. If this shows as unavailable or the number is incorrect, it won't work.

Look under the Phone settings > Caller ID  By default this is set to "Everyone". If you have changed this to "No one" or "My Contacts" then it will not work.

Once the HTC has acquired the VOIP info it needs a WiFi connection.

Once you have a Wifi Connection you need to go on the BT screen and SELECT VOIP rather than just having it active. This will not usually work in other home screens

If everything seems to be in place, even if the symbols are all correct, it sometimes needs a kick from an incoming call before you can make an outgoing call.

BTSoftphone

This is a software version for a PC that's equivalent to the VOIP on your HTC or hub phone. If I understand it all correctly the HTC simply uses a similar program under the hood.

VOIP works in some places but not others

VOIP is IP based. It shouldn't matter where you are so long as you have an internet connection.
The ToGo phone won't work via GPRS, I assume because BT block it - makes sense.
Once you have your laptop working with softphone or your ToGo working then don't alter the VOIP settings
If you can get an internet browser connection then VOIP should work.
If it works on one connection but not another then it is likely that you need to open a port (I have no idea what port number) via the firewall
It is, of course, possible that some providers specifically block VOIP or BT based VOIP 

What do I do if I changed from 0560 BBTalk number to a geographic one & it doesn't work?

Pull your hair out then try this

http://www.beta.bt.com/bta/forums/message.jspa?messageID=27615#27615

BT, Please let me know when you fix the "We've got to update/reboot/overnight run the server" problem so I can remove this.
It would also help if you didn't hide all your contact numbers. 

VOIP Software

Skype

http://www.skype.com/intl/en/download/skype/windowsmobile/

Personally I've not found this to be very good at all on the HTC but it works OK for others. If anyone discovers any specific fixes please let me know.

Fring

http://www.fring.com/ allows you to communicate with messenger and similar services.

NB. Their software works with other SIP based providers too.

It seems you no longer need BT's software to use your BBTalk on your HTC
See the forum starting at this point