Nortel and Research In Motion, the developer of the BlackBerry mobile device, are teaming up to develop more functionality for BlackBerrys.

The companies announced Monday plans to add multimedia and telephony services based on Internet Protocol technology. They are demonstrating applications at the VoiceCON convention this week in Orlando, FL.

The services will provide secure communications solutions across corporate enterprise networks, the companies said. The new applications are usable with the BlackBerry 7270 model.