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| Roaming charges: Hardware hunger hits Wi-Fi | |   | |
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| Airport Express leads the new breed of consumer APs
Those doggoned engineers have finally gotten around to revamping the hardware that most of us use to wirelessly connect to a network. As Larry discovers in this month's Roaming Charges, the imposing blue Linksys box is about to give way to a whole new crop of consumer-oriented access points (AP) that work with Windows and the Mac OS. True to trend, these babies are smaller, lighter, and built to deliver everything from AirTunes to pizza. Well, maybe not pizza. Hardware is usually taken for granted by users, who just want the goods it provides. No one really cares much what's inside a TV set, for example; or, for that matter, a wireless LAN. The thing is, these days it pays to know a thing or two about the inner workings of your WLAN. Most brands have moved past the stage where access points were interchangeable, and competition among vendors has driven prices down to the point where a major electronics retail chain will now sell you one of the 802.11 varieties (in either b or g flavor) for about $40, which is less than half of what it would have cost a year ago. Because most APs are platform independent, you can use them with whatever sort of computer you have. With APs becoming such a commodity, manufacturers need to differentiate their products from the other boxes out there. And this is leading to the rise of APs that are backward-compatible variations of the original idea of an AP, but offering considerably more bang for your buck. In this month's Roaming charges I'll show you four new APs that integrate hardware, software, and forward-thinking design for exceptionally exciting results. They all share one thing in common: they're reengineered versions of first-generation APs/routers, such as the signature blue one from Linksys. Netgear's wireless extension cord But there's more to this box than just wireless connectivity. WGR-101 implements NAT routing, which can obscure the actual IP address to one that a corporate network expects. It also offers a stateful packet inspection firewall to limit control of your ports to the hardware. A VPN mode using IPSec (and PPTP pass-through) enables you to communicate with systems that have a VPN front end. Netgear says that the WGR-101 is Wi-Fi Protected Access (WPA) upgradeable, although it ships with 64- or 128-bit WEP encryption as its standard feature. WGR-101s also come with an externally-accessible switch for setting the user mode to single or multiple. In single-user mode, only one user can connect at a time. If you're in a hotel and you don't want the people in the next room to piggyback onto your wireless connection, you'll probably choose single-user mode. Multiple-user mode is for the times when more than one person needs to share the AP. The mode switch is a small feature in concept, but it's the kind of detail that makes for real usability, which is something I greatly admire. Netgear's new box does present one usability barrier, however. The company says you need Windows (98 through XP) and a Pentium-class computer to use the device. My hunch is that the WLAN is more platform independent than its documentation indicates (perhaps the system requirements are tied to the configuration detailed in the setup instructions), but I can't be sure without trying it out. So, Linux and Apple users are hereby warned that this product might not work with your computers. Router in your pocket Expanding wireless media The MP101 comes with software to locate music files stored on any PC that is available to its wireless network. The player can find files on a PC to which it has a direct wireless connection or to which it is connected through Ethernet LAN. The software then constructs a database that organizes the files by title, artist, genre, and playlist. If it has a high-speed Internet connection, the player can also recognize streams, in which case it uses its database to obtain music files as they are needed for playback. The player itself can be controlled by an included infrared remote. A four-line LCD display on the front of the unit gives feedback on what is active. The MP101 player is one example of a product trend that I think will become more prevalent in the near future. Its wireless functionality is tied to a specific, marketable purpose, in this case playing music. It's also an all-in-one solution, containing both the software and the hardware to enable users to easily transfer music from one point on a network to another. Apple to the core Like the previous incarnations of Airport APs, the Airport Express first serves as a wireless 802.11b/g base station, connecting to the Internet through a wired Ethernet link. The Ethernet port also allows it to connect to an existing wired LAN as a client (using a static IP address), thus making it an AP to that wired LAN. None of this is particularly special; in fact, so far, the Express is no different from the portable Netgear AP, except perhaps in price. Things get more interesting, however, when you note the two additional jacks on the small-sized Express. One jack is a USB connection for a printer. The other is a 3.5-mm headphone jack that can either deliver normal analog audio output or digital output through a fiber-optic connection into the same jack. The chip that does most of the grunt work -- such as routing the data and controlling the radio link and print serving -- is a Broadcom BCM4712KFB (see Resources). Analog and digital audio output is handled by a Texas Instruments PCM2705 DAC (see Resources). Things really heat up when you see how the Express (or AX, as it has been dubbed by the user community) works with iTunes 4.6 and OS X 10.3. Music that would have been played through the Mac's speakers is now routed to the AX, which then connects to a remote stereo. It's like remote printing through the USB port, only for music. The all-Airport network Some of the built-in Mac network functionality shows up in unexpected (but perfectly logical) ways in AX use. For example, a printer plugged into the AX simply appears to the user through the Rendezvous autoconfigure technology (which has been renamed OpenTalk due to copyright conflicts) when the wireless network is active. To use a printer, you just select it in the Print dialog as a Rendezvous printer, the way you would with any other network-connected remote printer. It can even be made to come up as default printer so you don't have to reselect it every time you need to print. And there's more (of course there's more). In a homogeneous (all Airport Extreme) network, the AX can function as a remote using the main station's Internet connection, or as a relay enabling other AXs to connect to the main station. In this way, the AX effectively extends the range of the main station. Apple calls this sort of network a wireless distribution system (WDS). A WDS transforms a wireless channel into a duplex system, thus cutting each AP's available bandwidth in half. Fortunately, the available speed, even cut in half, is still better than DSL or cable. In fact, the only real downside to Apple's WDS, as previously mentioned, is that it theoretically doesn't work if you have non-Apple AP hardware driving your network. Fortunately, there's a workaround to this little hurdle. Pump up the volume Now, iTunes can also play Internet radio streams . But let's say that (like me) you connect to the Internet through a non-Apple AP. If you feed the radio to the AX and, hence your stereo, you'll have to wirelessly connect to the AX and not to the Internet. This little limitation seems to greatly decrease the utility of the AX in a heterogeneous network; except that I found a way around it. Circumnavigating the Apple Figure 1 shows the initial DHCP client table before you attach the AX. The router connects using Ethernet to the DSL, although that connection's not shown here. The router's IP numbers are divided through a subnet to establish both a wireless connection and an Ethernet connection. The Ethernet goes to the G3 tower and provides the tower's Internet connectivity. The tower connects to the AP through PPP, which is configured through the PPP pane of the G3's Network Preferences panel. Figure 1. The initial DHCP client table In Figure 2, an Ethernet cord is connected to the AX and plugged into the Linksys. The DHCP server assigns it an address as shown in the additional entry in the DHCP client's table. When the Airport Admin utility is opened up (foreground), it shows the AX and the Internet address it has been assigned. Note that the IP address might not show up in Admin until you perform the following configuration steps on the AX. Also note that the MAC (Media Access Control) address for the Ethernet link shows up in both the DHCP listing and Airport Admin. Figure 2. The DHCP server assigns an address Figure 3 shows the configuration option section of the Airport admin utility for the AX selected in Figure 2. The AX is first configured to be a new wireless network under the top, left Airport tag. In that configuration, radio channel six is assigned to the AX, because the Linksys is on channel one. These two channels are far enough apart in the radio spectrum not to interfere with each other As shown below, configure the AX to connect to the Linksys through DHCP over Ethernet and then use the IP address allotted. The MAC address is the router's, because it's the device that connects to the Internet. Figure 3 also reveals a nice shortcut: if you go to the WDS tab and choose the primary WDS base station from the provided pop-up list, the WDS base station's MAC address is automatically placed in the correct field in the pane. Figure 3. Configuring the selected AX Figure 4 shows an important checkbox: it seems that to make the WDS magic work, you must turn off distributing IP addresses. Also see the notes at the bottom of the page. Figure 4. Distributing IP addresses must be off! Figure 5 shows more of the WDS setup. The AX is the remote and the AP is the main station (the one with the Internet connection). Finally, the Linksys is chosen as the remote unit's wireless connection. iTunes is connected to the Internet through the Linksys. The music from iTunes bypasses the Airport connection preferences you just enabled and wirelessly streams to the AX and the connected stereo, keeping the AX's wireless connection occupied. (Remember that while you're doing all this music stuff, you could also be printing out a document on a USB-connected printer. If that printer needed Internet access, the Ethernet connection between the AX and the Linksys could provide it without infringing on the wireless connection. Pretty tricky, no?) The three points at the bottom of the screen shown in Figure 5 are most instructive. Figure 5. Configuring the WDS panel Finally, Figure 6 shows what iTunes looks like while playing Internet radio and streaming it to the AX. In fact, I'm listening to Internet radio as I write these words. The connection has been active for over two hours without any dropout or stuttering. Note the remote connection button at the bottom right of the panel. Figure 6. Reconfigured iTunes panel In addition to audio gratification, this entire escapade has had a salutary effect on the effective range of my hybrid WLAN. The range of my heterogeneous wireless network has been significantly extended from having just two wireless APs present. It's not just set up as a WDS that shares one linkname. I do have to manually connect to each of the APs as I change position instead of having the WDS software do it for me seamlessly, but I can live with the inconvenience to get the better range. An important note for Windows users Wrong, Bucky. Apple has learned a lot from the bi-platform iPod. If you use W2K or XP, you basically can do everything I've described thus far on your machine (if it's Wi-Fi rated). W2K users won't be able to use some of the setup assistants, and XP users need the wireless configuration software from Microsoft present; but it's basically the same deal. Apple includes Windows versions of the setup, administration, and iTunes programs with the AX that work the same way as the Apple programs. Oh, to print remotely you might have to enter an IP address for the printer because you don't have OpenTalk available to you; but that shouldn't be a deal breaker. In conclusion With all four of the solutions profiled here, the key is how the hardware, by integrating with the user's software, has become part of the overall solution. AX needs iTunes as much as iTunes needs AX; and together the two deliver a more complete solution to the user. In the end, the user gets better and more for less. Not a bad deal, when you think about it. Larry's tip of the month Acknowledgments Nathalie Welch and Anuj Nayar of Apple PR got me both the hardware and the software that I needed to write this column. Thanks to all of you.
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Larry Loeb has written for many of the
last century's major "dead tree" computer magazines, having been --
among other things -- a consulting editor for BYTEmagazine and
senior editor for the launch of WebWeek. Larry's latest book has
the contractually obligatory title of Hackproofing XML and is
published by Syngress (Rockland, MA). He's been online since