The market for unified communications (UC) infrastructure is expected to hit $4.8 billion by 2015. That's the word from ABI Research, which in new data released this week also predicted growth in the integrated UC suites market, and that for VoIP, both on-premises and hosted services models will grow, as well.

According to ABI, IP PBX vendors will ship a little over 35 million IP lines --- including native IP and hybrid lines -- during 2010. Overall VoIP revenue growth will come as competition between hosted VoIP providers and vendors that provide customer-premises equipment heats up, especially as both camps try to undercut the other on price and outduel each other on features.