The world enterprise telephony systems market is estimated to have shipped 37.3 million lines in 2009--down 20.4 percent year over year from 2008.

My colleague Alaa Saayed recently completed Frost & Sullivan’s latest research on the worldwide enterprise telephony market. Here's a quick look at some of the highlights on the platform side; clients can download the full report at www.frost.com.

* The world enterprise telephony systems market is estimated to have shipped 37.3 million lines in 2009--a growth rate of negative 20.4 percent year over year from 2008.

* Traditional systems made up 25.8 percent of total line shipments, declining at a rate of 18.1 percent year over year. NEC was the undisputed market leader in this category, with around 3.6 million TDM lines shipped; it's followed by Panasonic and Siemens.

* The decline in traditional-line shipments is expected to be even greater in the coming years as customers continue to acknowledge the value of IP communications and vendors gradually phase out legacy TDM/KTS PBX systems.

* IP systems (including converged and native IP) accounted for 74.2 percent of total line shipments, declining by 21.2 percent in the base year. The decline was mainly due to the economic recession and Nortel's collapse.

* Cisco was the IP market leader, with 18.3 percent market share, followed by Avaya (15.7 percent) and Siemens (14.5 percent).

* Cisco was the market leader in total line shipments, with 13.6 percent market share, followed by NEC (13.3 percent) and Avaya (12.9 percent).

* The world enterprise telephony systems market is estimated to have generated $5.7 billion in 2009, a 24.9 percent decline.

* The market is projected to modestly grow at a compound annual growth rate (CAGR) of 1.1 percent over the seven-year forecast period.

* Traditional systems made up 21.4 percent of market revenues, declining at a rate of 27.3 percent. NEC was the market leader with a 33 percent market share, followed by Panasonic, Avaya, Nortel and Siemens, in that order.

* IP systems (converged and native IP) accounted for 78.6 percent of market revenues, declining at a rate of 24.2 percent. Avaya’s voice system market revenues were greater than Cisco's, with a total market share of 17.1 percent.

* Overall, Avaya is the enterprise telephony platform revenue market leader with a market share of 15 percent, followed by Siemens, Cisco, NEC and Alcatel-Lucent.

* Frost & Sullivan believes that both IP line shipments and revenues will continue to outpace TDM line shipments and revenues, with the share of TDM shrinking to less than 10 percent at the end of the forecast period (year 2016).