A guide for configuring and Unlocking your Windows Mobile 6 Smartphone

For example your T-Mobile Dash, T-Mobile Wing GSM Cellular, HTC S630, HTC TyTN II, HP iPAQ, etc.

The WM6 OS generic version has the ability to be configured to make VOIP calls. But many providers remove this option, not wanting to encourage VOIP use on their network.

You can however put it back by installing the WM6 VOIP cab file and then a SIP configuration tool to enable you to enter your own SIP provider.

Fill in the SIP Configurator with the following info:

User: your_sip_number
Password: your_password
SIP Proxy: fonosip.com
Use Outbound Proxy: No
Stun Server: stun.fonosip.com

Once you have everything configured you can make a call, but remember you need to be connected over Wi Fi - you can make calls over 3G if your phone supports it, but to do this you will need to enable it via your SIP Conf Tool by going to Tools > Sip Over 3g/Gsm > Enable Via Reg.

Fring

As an option you can use Fring. It is a gateway program that allows users to make free VoIP phone calls from a Windows Mobile 6 phone.   Fring also allows multiple live chat sessions through Skype, Google Talk, MSN Messenger, and SIP

Fring is unique in that it caters for many different SIP providers  - it's a nice utility and well worth checking out.

Windows Mobile 5

For windows mobile 5 you can try www.go-sip.com or use the SJlabs SJPhone free softphone

Troubleshooting

Unlock your HTC Windows Mobile device for unsigned applications and certificates howto