The new wave of IP wired sets comes as wireless options proliferate. Cisco Systems, Avaya and other major telephony vendors showed off numerous Wi-Fi business phones at the Interop trade show recently in Las Vegas. For employees on the road, there are dual-mode phones that can work with IP PBXs (private branch exchanges) for features such as extension dialling and can get better coverage in the office by switching to Wi-Fi. New software also can bring cell-only phones into the PBX fold.

In this light, increasingly elaborate desktop IP phones that often are more expensive than wireless devices are coming under fire.

"Why does my $200 cell phone have ten times the functionality of my thousand-dollar IP phone?" remarked Yankee Group networking analyst Zeus Kerravala.

Hanging on to the desk set is partly a matter of tradition. People still relate to their physical phone. It's like their office space. It's very near and dear to their hearts.

"Desk phones are 50-year-old dinosaurs. They shouldn't be there anymore," said Gartner's mobility analyst Ken Dulaney. "All the desk phone does is forward calls to cell phones."

Yet Dell'Oro Group estimates the market for IP desk phones will boom in the coming years. The market research company said 11.3 million were sold last year and the number will rise to 34 million in 2010. The growth will come even as PC softphone sales grow from 2.6 million to 8.6 million, said analyst Alan Weckel. While strictly Wi-Fi phones will settle into vertical markets such as hospitals, which restrict cell-phone use, dual-mode phones will also be popular, he said.

Hanging on to the desk set is partly a matter of tradition. People still relate to their physical phone. It's like their office space. It's very near and dear to their hearts.

Wired phones still tend to have better sound quality than wireless, vendors and analysts said. In some cases, they include more phone-system features than their wireless counterparts. And for softphones, the PC's reliability and startup time are issues, Weckel said.

The right choice may depend on the user and the setting: dual-mode phones plus laptop softphones for employees who travel frequently, and dedicated phones for workplaces without PCs.

But while they continue to sell desk phones, major vendors are pushing alternatives. Cisco provides software for Nokia E-Series dual-mode phones that extend office phone system functions to the handsets. The phones are already available in Europe and in Japan through NTT DoCoMo, according to Chris Kozup, mobility solutions Marketing Manager at Cisco. Avaya also is working with cell phone vendors on making dual-mode handsets work with its software and will reach more phones through its acquisition of Traverse Networks last year, said product manager Jamie Lawson.

"The future is going to be a future of choices," said analyst Elizabeth Herrell of Forrester Research. However, no one wants to have four phones, she said. One solution may be base stations that turn wireless phones into desk phones while an employee is at the desk. Neither of the two biggest IP phone makers has quite embraced this idea, however. Cisco has a cradle that charges its 7921G Wi-Fi phone and acts as a speakerphone, but the calls still go wireless. Avaya lets users treat a mobile and a fixed phone as one, so when one is off the hook the other is, too.

Desk phones can't go away overnight, if only because of an installed base estimated by IDC at about 500 million. Even Gartner's Dulaney thinks it will take five to seven years for wireless office phones to replace wired. In the end, users will have to push vendors to change course, Forrester's Herrell said.

"No one's going to walk away from that revenue stream of business phones until the users decide they don't want it," she said.