Zeroconf and its Bonjour iteration are intended to let computers attach to a network, find each other and communicate usefully "without needing a man in a white lab coat to set it all up for you," as Cheshire says. He identifies four main requirements for Zeroconf, and the services used to meet these requirements in implementations like Bonjour:
+ Allocate addresses without a DHCP server, using IPv4 Link-Local Addressing.
+ Translate between names and IP addresses without a DNS server, using Multicast DNS.
+ Find services, like printers, without a directory server, using DNS Service Discovery.
+ Allocate IP Multicast addresses without a MADCAP (Multicast Address Dynamic Client Allocation Protocol) server, a future project.
And it needs to do all this without causing harm when the computers are part of larger, configured networks.
Bonjour is what gives Apple products their plug and play networking capabilities - they just network when they're connected to the same LAN. AirPlay builds on this, by letting iOS devices and Macs stream multimedia files, or selected Web-based content, via an Apple TV box to AirPlay enabled speakers or flatpanel displays, all with just a few finger taps or mouse clicks. It's very compelling in the small Wi-Fi networks typically found at home, for example. But it's not so compelling today on larger, more complex networks, at least as they are designed today.
The explosion of iOS devices on campuses, and in businesses, along with Apple TV and AirPlay, is generating a huge demand by users. They want the same kind of simple connectivity they get at home but in their class rooms, conference rooms, and dormitories.
"[T]oday's users also want to drag the likes of Apple TV and other AirPlay/Bonjour-enabled toys into the classroom and conference room," writes Lee Badman, wireless technical lead at Syracuse University, an Educause member. He's also a blogger for Network Computing, where he recently posted an overview of the Bonjour issues driving the petition. "Indeed, Apple promotes it: 'AirPlay Mirroring is made for an audience. Because with a click, what's on your Mac is also on your HDTV. It's easy to set up with Apple TV. Show web pages and videos to friends on the couch, share lessons with a classroom, or present to a conference room.' The problem is, these Apple devices are far from being good network citizens."
"With growing user demands, higher education network managers are attempting to unify their voices and ask for Apple to step up to the plate," Badman writes. "Kludgy workarounds and dedicated networks for a handful of devices are not sustainable solutions."