Intel has become the first chipmaker to support for the latest version of Cisco Compatible Extensions (CCX), Cisco's controversial proprietary add-ons to standardised Wi-Fi gear.

On Wednesday, Intel said it had achieved CCX 4.0 certification with the Intel PRO/Wireless 3945ABG Network Connection, part of the Centrino bundle of chips. The certification is designed to ensure wireless clients are compatible with Cisco's Aironet range of wireless access points - and more specifically, with proprietary additions that handle security, manageability, roaming and other features.

"With this certification, future Intel Centrino mobile technology customers can be assured that their devices are designed to be supported," said Jim Johnson, general manager of Intel's Wireless Networking Group.

The Intel chip involved is intended for the next generation of Centrino, shipping in early 2006. The announcement is part of a wider deal between the two companies around compatibility. The two companies have collaborated on new features called Business Class Wireless Suite, which includes CCX 4.0, Intel PROSet/Wireless Software v10 and additional improvements for roaming and IP telephony.

Cisco says CCX is designed to keep enterprises up to date with WLAN technologies that may not have been integrated into standards yet, arguing that standards bodies such as the IEEE can't keep up with the pace of change. CCX builds new features into Cisco routers and keeps client chipmakers compatible.

Intel, IBM, HP, Atmel, Atheros, Agere, Texas Instruments and Marvell are among the CCX programme's supporters.

The close collaboration between Intel and Cisco is not to everyone's taste, however. Both companies dominate their respective markets. While exact market share figures for Centrino are not usually published, Intel is the biggest maker of notebook WLAN chips, besides controlling more than 85 percent of the world market for all PC processors. This is all the more remarkable in that Intel only began making wireless laptop chips with the introduction of Centrino in 2003. Cisco's Aironet APs have by far the largest share of the WLAN AP market, although the company faces stiff competition.

Some in the industry fear a Wintel effect, with Intel and Cisco creating de-facto standards that undermine organisations such as the IEEE and the Wi-Fi Alliance.

Cisco introduced enhanced security via CCX at a time when enterprises were awaiting an improved system from the Wi-Fi Alliance. Currently, Cisco is focussing on roaming and network management elements, which are also addressed in upcoming standards such as 802.11k.