All Roads Lead to Rendezvous

Your flight from the East Coast was delayed -- you dash into your company's West Coast office with only a few minutes before the big meeting. Undaunted, you pop open your PowerBook and hook up to the local AirPort network. You calmly choose Print and notice that the printer on the table next to you is selected in the Print dialog box. With a minute to spare, you open iChat, find the names of the people you're supposed to meet, and let them know that you're waiting in the conference room.

The report you wrote is a hit: a colleague wants to use one of your graphs in her own presentation. Still sitting at the table, you connect to her computer via document-collaboration software and paste your graph directly into her document.

All these feats are made possible by Rendezvous -- the networking technology introduced with Mac OS X 10.2 -- which makes finding resources on a network incredibly easy. With Rendezvous, there are no network configurations to fool with (or computer-support wizards to beg for help). Instead, your Mac and Rendezvous-savvy hardware and software do the communicating for you, and you reap the benefits.

In this article, we'll reveal how Rendezvous works, and we'll check out new products that take advantage of Rendezvous's abilities.

Simplicity versus Compatibility

Many Mac users have become accustomed to ignoring the nuts and bolts of networking: they plug in the Ethernet cables, and the Macs work. But it's taken a lot of effort behind the scenes to make that possible.

Apple-Only Ease In the past, we depended on AppleTalk. AppleTalk setup requires no special configuration -- you plug in devices, and they find one another over the network. It provided Mac users and administrators with instant and continuous access to networked services, such as file sharing. From an AppleTalk browser (the old Chooser, for example), you could view a server or network printer by name and connect to it in one step.

Cross-Platform Needs But AppleTalk is a Mac-only technology in a cross-platform world. These days, most network hardware, PCs, and printers -- as well as other devices -- don't support AppleTalk. They use TCP/IP, the language of the Internet. Universal TCP/IP support provides both seamless communication with the Internet and a single networking medium that all computer makers, software vendors, and users can agree on.

As a result of this, Apple -- while continuing to support AppleTalk in OS X -- has started to focus on TCP/IP. This has made Macs more compatible with other computers, but it's also been a step away from Apple's goal of providing easy-to-use technologies. Indeed, trouble with printer configuration has vexed many an OS X user, and even Mac-only networks require some level of administrative configuration to allow Macs to obtain IP addresses.

Best of Both Worlds Enter Rendezvous, which makes it possible to create an instantly usable TCP/IP network -- or to find and use resources on an existing Mac network -- all without knowing or typing an IP address or URL. Rendezvous is based on an industry standard called zeroconf, developed by the Zeroconf Working Group of the IETF (Internet Engineering Task Force).

A slew of printers -- including those from Brother, Canon, and Hewlett-Packard -- quickly joined the ranks of Rendezvous-enabled products, many of which are shipping now. Some others are Apple's new iTunes 4, Aspyr's NASCAR Racing 2002 Season, and the World Book Encyclopedia 2003, from World Book (bundled with all consumer Macs). Shareware authors have also been experimenting with Rendezvous-based tools that facilitate document collaboration, remote music playback and file sharing, and more

The Trouble with IP Addresses

To communicate via a TCP/IP network, either locally or over the Internet, every device must have an IP address. Your Mac gets its address from a server or uses an address that is preassigned by an ISP or network administrator. Either way, a router or server on your network must guarantee that all devices have addresses that are accessible to all the others.

That makes it challenging to create a temporary network (so you can copy photos from your PowerBook to your brother's, or hook up a few friends' computers for an afternoon session of Warcraft III, for example), or to build one when there is no router or network administrator who can set up IP addresses or servers.

It also creates difficulties for members trying to find resources, unless they know where and how to find others' IP addresses. Say your colleague in marketing published a Web-based newsletter on his computer -- you can't access it unless you know his Mac's IP address.

Problems also arise when you want to chat with a friend whose instant-messenger nickname you don't know, or when you need to use a local file server or printer. For one thing, your networked Macs often get a different IP address from a DHCP (Dynamic Host Configuration Protocol) server each time you restart them. So the bookmark you saved for the local MP3 server may not work the next time you try to use it.

The Rendezvous Way Instead of requiring that you know IP addresses, Rendezvous-enabled applications provide a real-time, name-based view of current network resources. You can use Apple's Rendezvous-enabled browser, Safari, to look at files on Joe's Mac over the network, and you can use iChat to talk with Joe, whether or not you know his address. Since Rendezvous-enabled applications find you, not vice versa, you may discover hidden treasures on your network -- such as the guy down the hall in your dorm who's hosting a network game.

Rendezvous also makes new kinds of sharing possible because it simplifies direct communication between networked computers, especially in environments where ad hoc networks are created, used, and then dismantled. If, for example, you meet your law-school study group at a coffee shop, you can create an AirPort network and, with Rendezvous, quickly set up file sharing or a document-collaboration session with a program such as Math Game House Software's $20 iStorm 2 (see "Work Together"). And you don't need to set up TCP/IP or exchange IP addresses. Shared resources on the new network appear in each person's Rendezvous-enabled applications and can be accessed with a click.

Later, when you go to the law library to study, you can connect to the library's AirPort network and print your group's document on a Rendezvous-enabled printer without ever opening OS X's Print Center. Finally, when it's time to relax at home, you can use iTunes to find your roommate's MP3 server and listen to some music over the network. (To understand how this works, see "The Method behind the Magic," which you can find by following the sidebar link at the bottom of this page.)

Rendezvous in the Real World

If you have OS X 10.2 or later installed on two or more Macs, you can start using Rendezvous right now. Just fire up iChat on two machines that are already connected by a network (Ethernet or AirPort).

Chatting and Browsing Once Rendezvous is enabled on each Mac (iChat: Log Into Rendezvous), you'll see members of your network in iChat's Rendezvous window. You don't need to establish an instant-messenger account to chat locally, and you don't need to enter account names for your coworkers. From here, you can exchange messages and files with anyone who logs in to the network.

Apple's Safari Web browser provides another way to use Rendezvous instantly. Using Rendezvous (Preferences: Bookmarks: Include Rendezvous), you can view locally hosted Web sites from the Bookmark bar or Bookmark menu. Any Mac with Personal Web Sharing turned on will appear by name (Patsy's Web site, for example) on the bar or menu in Safari. Even if a site is publicly available, Rendezvous gives you a local connection to it. As users enter and leave the network, Rendezvous updates Safari's bookmarks. If you were using a browser that didn't support Rendezvous, such as Internet Explorer, you'd need to know and enter the local site's URL, including that machine's IP address.

Chat and local Web browsing may seem like relatively limited ways to communicate, but Rendezvous may just allow these business tools to be used more frequently. Chat, for example, lets people hold conversations or quickly exchange files while getting other work done, and it provides a record of the conversation should they need it. Because Rendezvous updates the iChat window dynamically, you'll always know who is available and who has gone offline. Lastly, organizations that restrict access to instant-messenger networks can still allow Rendezvous-enabled local chat, because it doesn't require that users have access to the Internet.

Local Rendezvous Web sites can be used as business tools, too. Build a company intranet, or use locally hosted pages as a prototype for your company's public site. Rendezvous's way of discovering other devices on the network, multicast DNS (domain name system), makes it possible to deploy local Web sites even if a DNS server isn't present, or if a system administrator doesn't want to add local Macs to the DNS server. Though a PC, and a Mac running a version of Mac OS earlier than OS X 10.2, can host local Web sites, Rendezvous-capable browsers will show you only sites that are hosted on Rendezvous-using Macs.

Printing Made Easy Printing often bedevils network managers, especially in cross-platform environments. AppleTalk made it easy for Mac users to locate and use a networked printer, but TCP/IP and the prevalence of Windows-based network printing have made printing a challenge for many OS X users. Rendezvous attempts to bring AppleTalk simplicity back to the Mac, regardless of whether a PC print server hosts the printer.

A Rendezvous-enabled printer can be connected to a TCP/IP network or directly to a Mac; it broadcasts its name and configuration information via Rendezvous naming and service discovery. Printer makers, including Xerox, Epson, Canon, and Lexmark, have announced their intention to use Rendezvous in their printers. Brother's $500 HL-5070N laser printer and Hewlett-Packard printers that include or support the company's JetDirect Ethernet and wireless print servers now all support Rendezvous. You can also connect a USB printer to Apple's AirPort Extreme Base Station, to provide Rendezvous printing to wireless Macs. The Base Station acts as a print server for the network.

These printers don't require network configuration. Even if a network administrator sets up PC-based printer access and queues, Rendezvous-capable Macs on the network simply discover and use the printer. With a Rendezvous printer on the network, you just select Print. You don't need to use Print Center to add or configure a Rendezvous printer, though you can use it to select one if multiple printers are available.

Rendezvous also provides easy access to printers with Web-based configuration, such as Brother's HL-5070N. The printer appears as a Rendezvous Web site in Safari's Rendezvous Bookmark bar. From the Web interface, you can manage the print queue and the printer.

Sharing Files Next to printing, file sharing is probably the most common activity on a local network. After all, most people need to exchange files with colleagues or retrieve them from a central server.

Right now, users of FTP servers will gain the greatest benefit from Rendezvous file sharing. That's because FTP clients don't display local file servers without Rendezvous. A number of shareware programs, including Xnet's $25 Captain FTP 2.2.1 and Panic's $25 Transmit 2, provide Rendezvous access to FTP servers on a local network -- useful if you use FTP servers for local file storage. Xnet also sells a Rendezvous-like file server (based on zeroconf) for Windows, called Crocodile.

Play Date Multiuser gaming has been around for a while, but most of these applications connect over the Internet and require that you know the IP addresses of opponents. Rendezvous-enabled gaming works on a local network and lets competitors see each other by name.

Aspyr's $39 NASCAR Racing 2002 Season is the first Rendezvous-enabled game. The company says that as many as 43 players can compete locally on NASCAR tracks. On a Rendezvous network, you can join a local race, and see and chat with other racers.

New Frontiers

If the crop of commercial and shareware collaboration and network-sharing tools is any indication, Rendezvous has fueled the imaginations of Mac developers. Database heavyweight Sybase has lent Rendezvous a cross-platform boost by adding support for OS X to its enterprise-level products. Sybase's Adaptive Server Enterprise 12.5 for Mac OS X runs on Apple's Xserve and uses Rendezvous to discover databases automatically. Chaparral employs Rendezvous to manage its RIO RAID Storage Controller, another product found in corporate back offices, where Apple has often been shut out.

Mixed Media On the home front, TiVo, maker of the popular digital video recorders, plans to use Rendezvous to allow TiVos to discover networked Macs. You'll be able to play your Mac's sound files and display its photos on a TV.

Apple's coolest and most visible implementation of Rendezvous can be found in iTunes 4, which allows you to discover and connect to a music server from a remote Mac and play MP3 files from the remote machine (see "Play Together"). You can share individual playlists or your entire music library with as many as five networked Macs, and iTunes lets you password-protect each iTunes server.

A few shareware authors have tried to create similar applications that use Rendezvous to locate iTunes libraries and deliver music over a network. Slim Devices' $229 SliMP3 MP3 player provides a Web-based interface to both the player and a local iTunes server. You can also use the free SliMP3 software alone to connect to the Web-based interface from Safari's Rendezvous menu.

Other Rendezvous information-sharing applications promise support for document sharing and collaboration. Math Game House's iStorm lets many Rendezvous users work on a text document simultaneously. And the iChalk 2.02 module, included with iStorm and available separately ($10), is a Rendezvous-enabled color chalkboard. The $68 World Book Encyclopedia 2003 brings Rendezvous to the educational realm. With the encyclopedia running on multiple computers -- in a computer lab, for example -- students can add notes to entries in their copies of the encyclopedia and share those notes with others. When a group project is complete, one person can gather all of the notes and create a final report, using World Book's tools.

Just Browsing The majority of Rendezvous-enabled tools focus on a particular network application, but the increasing number of Rendezvous browsers will let you see a complete view of services available on your network. Most give you a list of local services, organized by protocol.

Most of these freeware and shareware tools are still in development. You can use them to locate a Rendezvous service, but you generally can't yet access the service by selecting the item. The most useful browser so far is Toxic Software's iRoster (still in beta), which shows available Rendezvous services in a Dock menu.

The Last Word

Rendezvous is easy to use and cross-platform, and it has already begun to spawn interesting products. As AirPort wireless technology makes temporary networks more common, and as OS X 10.2 finds its way onto more Macs, Rendezvous will help prove Apple's claim that the Mac is the best computer for the network -- and the easiest one to use.

Subscribe to the Help Desk Newsletter

Comments