Avaya is to buy Ubiquity Software, a developer of software applications using SIP technology.

The deal, worth £74.3 million (US$144 million ), will help Avaya provide support to network operators and enterprises migrating to all-IP (Internet Protocol) networks, said the company.

Avaya designs, builds and manages communications networks for more than 1 million companies worldwide.

Ubiquity develops SIP-based communications software to service providers, ISVs and OEMs around the world.