Bonjour, originally called Rendezvous when introduced in the early 2000s, is Apples latest implementation of , which is a group of open Layer 2 protocols to automatically and quickly set up an IP network, without having to set up services such as Dynamic Host Configuration Protocol, DNS, and DNS Service Directory. ( at a page maintained by Stuart Cheshire, Zeroconfs pioneer, who was later hired by Apple.)

And in simple home Wi-Fi networks, thats just what happens: Apple clients broadcast for services, the services identify themselves, and client and service simply connect, paving the way for specific Apple protocols like AirPrint for printers and AirPlay for sharing multimedia among Apple clients via an intervening Apple TV box

But the strengths of Bonjour become problematic in more complex networks, which now can have hundreds, thousands or tens of thousands of iPhones and iPads advertising for services, but unable to connect if theyre on separate subnets. And the discovery traffic can, according to some colleges and universities, sometimes hit 90% of the network load. The problems are pressing enough that last week a group of higher education IT managers finalized a petition to Apple, asking for a range of Bonjour, and related, changes to make the protocols better citizens on enterprise networks. [See ""]

Cisco is the third WLAN vendor to address these issues with a Bonjour gateway. , first announced in March. Rival Aruba Networks announced a similar capability, also in March, and is expected to release it before the end of 2012.

On a Cisco WLAN, Apple clients will advertise for Bonjour services, just as they do now, says Chris Spain, vice president of product marketing for Ciscos wireless business unit. The Cisco access point then will tunnel those requests back to the WLAN controller, and match them with an inventory of available AirPrint printers, Apple TVs, iTunes libraries and the like on any subnet in the enterprise network. The controller identifies the user, matches the authenticated user with his or her access privileges and grants access to the requested Bonjour service or not, based on group policies.