Dell'Oro Group reports that IP lines for the PBX market are forecasted to decline for the first time ever in 2009. Notwithstanding, VoIP penetration will continue to grow this year, albeit at a slower pace compared to the previous years.

According to the report, Cisco, Avaya and Nortel had the most IP line shipments in the quarter. The report also revealed that despite VoIP transforming the industry for over a decade, the IP line shipments for the eight largest vendors in the market, namely Aastra, Alcatel-Lucent, Avaya, Cisco, Mitel, NEC, Nortel and Siemens averaged only 49 percent of total line shipments in the quarter.