Apple feature: Extreme revolution

Apple feature: Extreme revolution

Apple's latest foray into the wireless world promises to change the way some small businesses, schools, and even home users connect to the Internet and their local networks.

With a name like AirPort Extreme, Apple Computer Inc.’s new networking technology might seem to be aimed at the X Games crowd, not business professionals. Nevertheless, the company’s latest foray into the wireless world promises to change the way some small businesses, schools, and even home users connect to the Internet and their local networks. What’s so extreme about AirPort Extreme? For starters, it’s faster -- as much as five times faster than earlier AirPort technology. It also features a number of improvements that help reduce interference, boost range, and may even make your networks more secure in the future.

Is AirPort Extreme the answer to your wireless needs? To find out, we took a look at how the technology works and who’s likely to benefit from it. Then we tested five AirPort Extreme -- compatible base stations to see which one offered the best Mac performance.

Understanding AirPort

Looking at the original version of AirPort, which appeared with the original iBook in 1999, is helpful in understanding how AirPort Extreme improves wireless networking.

The Wireless Boom AirPort was Apple’s version of IEEE 802.11b, a standard for sending and receiving data wirelessly at a rate as high as 11 Mbps, which is roughly the same speed 10BaseT Ethernet networks offer. (Of course, once you’ve factored in networking overhead and real-world conditions such as interference and multiple users, this speed actually translates into about 5 Mbps.)

Apple’s AirPort was the first truly affordable implementation of 802.11b, making the Mac a wireless leader. Eventually, hundreds of other companies jumped on the band- wagon. Now, 802.11b networking not only is found in homes and offices, but also powers fee-based hot spots, or public wireless networks, at more than 2,200 Starbucks cafés, a couple dozen airports, and hundreds of hotels, not to mention free community networks in many cities worldwide.

Over the years, however, the original 802.11b technology has worn a bit thin. As the demand for more-robust wireless networking grew, Apple began looking to a new wireless standard, 802.11g, which, with its usual flourish, it dubbed AirPort Extreme.

Unlike 802.11b, which is limited to 11 Mbps, AirPort Extreme allows raw speeds as high as 54 Mbps, or roughly half the speed of a 100BaseT network. (As with the original AirPort, this number is extremely optimistic. But even the more realistic expectation, 25 Mbps, is a big improvement over previous AirPort speeds.) Apple is one of several companies currently selling 802.11g gear, and even more products are scheduled to hit the market by summer.

How It Works Both AirPort and AirPort Extreme transfer data by first breaking it up into extremely short pulses that vary in frequency and duration. These pulses are then sent out over radio waves in the same 2.4GHz band that many cordless phones use. So there would be room for everyone, the available radio spectrum was divided up into 14 channels, 11 of which are available in the United States. But unlike cordless-phone or even Bluetooth signals, which can hop from one channel to the next, a base station is set to work on just one channel all the time.

If you picture the 2.4GHz band as a highway, a base station is a giant semitrailer that never veers from its one broad lane, no matter how many miles it travels or how much traffic lies in the road ahead of it. This means that the more people who are trying to send their data through a single base station -- and therefore a single channel -- the more clogged this lane becomes.

The Extreme Difference AirPort Extreme relieves some of this congestion by raising the speed limit to 54 Mbps. This boost in speed means not only that single users can transfer data more quickly, but also that more users can work on a network at one time. Whereas busy offices might have needed more than one AirPort base station to provide adequate speed to all its employees, AirPort Extreme, with its larger pool of bandwidth, can serve many users from a single base station, thus cutting down on equipment costs.

AirPort Extreme also solves some of the problems of coverage and signal quality found with 802.11b. Even though 2.4GHz radio waves can mostly penetrate solid objects, there’s always some reflection, especially off the metal in walls. As a result, the same signal arrives at a receiver at slightly different times. The 802.11b standard wasn’t good at differentiating a reflected signal from the original. So the farther you got from a base station (and the more surfaces you encountered), the worse 802.11b performed.

AirPort Extreme can better synchronize these reflections, so it can interpret signals from a greater distance or through more obstacles at higher speeds.

For even better coverage, you can attach an external antenna to your base station -- if it offers a connector (of Apple’s line, only the $249 Modem Edition supports external antennas). Dr. Bott (877/611-2688,, for example, offers two such antennas: the $100 ExtendAir Omni, which claims to extend your range as much as 250 feet in every direction, and the $150 ExtendAir Direct, which claims a range as far as 500 feet in any one direction. [Editor’s note: our initial tests with the Dr. Bott extenders didn’t show any marked improvement. We are continuing testing and will follow up in a future issue.]

Security Woes One flaw with 802.11b that AirPort Extreme won’t immediately solve, however, is security. 802.11b uses a security standard called WEP (Wired Equivalent Privacy), which scrambles data as it passes over your wireless network. But a number of flaws make it easy for crackers to write software that allows anyone to break into that encrypted traffic. While home users aren’t often at risk from crackers, this flaw has made WEP almost useless for businesses or other security-conscious users; smart businesses use their own encryption overlay.

The IEEE group, which sets the standards for wireless networking, has been working to fix WEP via a new standard called 802.11i, which promises government-grade encryption. However, it won’t be finalized until the end of 2003. In the meantime, the Wi-Fi Alliance, an industry group that certifies 802.11b devices, came up with a stopgap measure called Wi-Fi Protected Access (WPA). WPA contains some of the security advancements proposed in 802.11i, is backward-compatible (802.11i will likely not be), and extends AirPort-like simplicity to non-AirPort users.

Starting in May, WPA should be available in the form of upgrades to all existing equipment from non-Apple companies. Unfortunately, Apple hasn’t agreed to support either updated security system yet, which could make Macs less secure in networks that use the newer standard. (With WPA, some computers can use WEP, but it forces the whole network into a less secure mode.)

But there is promising news. The chips that Apple uses for AirPort Extreme are already designed to take advantage of the most advanced features of 802.11i, should Apple decide to follow the industry.

Going to Extremes

Is AirPort Extreme right for you? Well, it depends on how you use it. Having all the bandwidth in the world won’t make a difference if you don’t actually need it. If you use AirPort only to surf the Net from home, for example, you can almost certainly keep your old AirPort gear -- cable-modem, DSL, and dial-up connections are much slower than the maximum speed of even 802.11b (at least for the foreseeable future). But if you often move lots of data around a local network, AirPort Extreme may be the answer you’ve been looking for.

Speed Matters To see AirPort Extreme at its best, take the example of a design shop where 25MB Adobe Photoshop files are routinely sent from designer to designer, or where large projects are moved on and off network file servers. In this scenario, AirPort’s 11 Mbps would feel glacial -- as well as burn up nonbillable hours.

When setting up this work environment in the past, companies often turned to Ethernet for the answer. But adding 100BaseT Ethernet requires hiring special installers who drill holes, run cable, and charge what amounts to a few hundred dollars per network outlet.

On the other hand, adding AirPort Extreme costs just $50 to $100 per machine and $100 to $250 per base station. So creating a pod of 10 to 25 users sharing one base station could cost the same as wiring that installation.

But what happens when your business grows or changes location? Ethernet offers less flexibility in moving machines around and expanding your network. Adding another AirPort Extreme user, even temporarily, is a tiny cost compared with bringing in another jack. And wireless users can coexist on the same network as Ethernet-connected users.

Future Needs While most consumers aren’t yet moving huge amounts of data, this may change as bigger Internet pipes begin offering speeds higher than 11 Mbps, and home electronics begin routinely streaming video and audio to each other.

In fact, this future may not be that far off. Several companies are already demonstrating home networking devices, such as Macsense’s $199 HomePod (650/869-4828,, which lets you use 802.11b to stream music from your iTunes library to your stereo for playback.

Still, existing AirPort owners should look long and hard at whether they currently need the extra speed before buying a new AirPort Extreme base station. The upgrade would require new Macs in some cases, and the benefits might not be clear until we do live in that streaming-media future.


There’s good news for existing AirPort owners who decide to go Extreme. AirPort Extreme is completely compatible with the earlier AirPort standard. This means that if you’ve got an 802.11b card in your PowerBook, it can connect seamlessly to an 802.11g network -- and vice versa. But keep in mind that you’ll be connecting at the slower 802.11b speed.

For full-speed connections, you’ll need an AirPort Extreme card in your Mac and an 802.11g-compatible base station. But even then you may run into some compatibility glitches. Our tests show that just having an 802.11b machine on your AirPort Extreme network can slow down the traffic for everyone. Companies say that this will likely be fixed over time. AirPort Extreme Base Stations can be set to work only at the faster speed -- and thus shun any 802.11b equipment -- but most people setting up a network probably wouldn’t choose such a restrictive option.

Work in Progress There is one wrinkle in making the move to AirPort Extreme, at least anytime soon: 802.11g isn’t fully cooked yet. When Apple, Linksys, Belkin, and other companies started shipping 802.11g hardware in late 2002 and early 2003, the standard hadn’t been finalized. And that’s potentially dangerous. A wireless specification contains so much minutiae that even tiny changes could render equipment based on earlier versions incompatible.

But here’s the good news: The Wi-Fi Alliance recently announced it should be ready to test and certify 802.11g equipment soon after the standard is finalized by the IEEE, which is expected to happen in June or July. In the meantime, Apple and other companies will likely continue to offer software upgrades to bring AirPort Extreme in line with the latest draft of the specification.

The Last Word

AirPort Extreme is a promising step in making wireless networks a real alternative to stringing wire and drilling holes. For existing AirPort users who don’t move huge files over a network, or who aren’t suffering from coverage problems, there’s no compelling reason to upgrade right now.

But AirPort Extreme’s new speed and the Base Station’s bridging option make it a natural choice for businesses or schools looking to expand their networks in a more flexible and potentially less costly way than adding more Ethernet. It’s also a good investment for users who want to turn their homes into wireless wonderlands with access in every room, on every floor -- not to mention that backyard office.

Take Old Macs to Extreme

For Mac owners with older machines, upgrading to the zippy speeds of AirPort Extreme won’t be as simple as just popping a new card into your AirPort slot. That’s because the original AirPort card is based on a slow version of the PC Card format and can’t handle the speeds of AirPort Extreme. So Apple designed a new slot and card for AirPort Extreme, mimicking the mini-PCI format used in many Intel PCs and laptops. As a result, only Macs introduced or revised since January 2003 can use Apple’s new AirPort Extreme card.

But that doesn’t mean older Macs are necessarily out of luck: most modern Macs have either a PC Card slot, PCI card slot, or 10/100-Mbps Ethernet port and can handle 802.11g’s speed -- as long as they’re connected with the right equipment. And for that, you’ll have to look somewhere other than Apple.

PC Card PC Card slots (sometimes called PCMCIA slots) can be found in PowerBooks dating back several years, although pre-PowerBook G3 models generally don’t have the processor speed and network capacity to work with 802.11b. At press time, there were no Mac-compatible 802.11g PC Cards. But this will likely change as development gears up. Belkin (800/223-5546, has announced that it’s working on an 802.11g PC Card with drivers that will work under Mac OS 8.6 through 9.2 and OS X, but has pushed back its delivery date. Macsense says it expects to release an 802.11g update to its AeroNet Universal Driver, a Mac driver that currently supports an array of inexpensive 802.11b PC Cards, by late April.

Enterprising individuals are also contributing to the cause with a few lines of homegrown code. Nick Sayer, for example, knew that Apple and Linksys used chips from Broadcom and created a patch for OS X 10.2.3 that allows a PowerBook to use the Linksys 802.11g WPC54G card ( cat_airport_extreme_hacks.html).

PCI Card A PCI slot is found in all Power Mac G3 and G4 computers. However, the only wireless PCI cards currently on the market lack OS X support, and none of the companies offering Mac drivers have specifically said they will offer PCI support. Nick Sayer’s hack (mentioned previously) has been found to work on some Power Macs running OS X. But other users report not being able to boot up with the Linksys card installed and the hack enabled.

Ethernet For machines that don’t offer PC or PCI cards, such as the eMac, the iMac (all 10/100-Mbps Ethernet models), the Cube, and all iBooks, there is an interesting alternative: an Ethernet-to-wireless bridge that can convert an Ethernet network connection into wireless data. Although just connecting an Ethernet wire might seem to make more sense, bridging Ethernet traffic to a wireless network lets you extend your networks where you can’t extend wire, such as across a street, or to the other end of a house.

Linksys offers the $100 WET11 bridge (800/546-5797,, which can plug into a network of as many as 30 Ethernet-connected devices and bridge all their traffic to any wireless station, including Apple’s. Linksys says it plans to upgrade the WET11 to 802.11g speeds and sell it as the WET54G, although no official release date has been announced.

On the Range with Apple's New Laptops and AirPort Extreme

When Apple announced its new 12- and 17-inch PowerBooks with AirPort Extreme, it promised that the laptops would offer improved wireless range. That’s good news, since the range on the earlier-generation Titanium PowerBook G4 was far inferior to Apple’s iBooks. To determine just how much improvement PowerBook owners would see in the real world, we repeated our tests, pitting the new lap- tops against a white iBook and a Titanium PowerBook G4. We performed the tests first with the 802.11b AirPort Base Station (results in blue) and then the newer AirPort Extreme Base Station (results in red). In each case, we used MacStumbler 0.6b in OS X and measured signal strength on a scale of 0 to 100. Scores were averaged over a 60-second period (anything below 40 is considered a weak signal).

The 12- and 17-inch PowerBooks proved they could indeed live up to the iBook’s range, outreaching the earlier PowerBook every step of the way. The iBook’s range, however, decreased slightly on the AirPort Extreme network. -- macworld lab testing by becky waring and james galbraith

802.11g Base Stations

Apple’s AirPort Extreme Base Station was one of the first wireless products to take advantage of 802.11g’s speed boost. But it’s certainly not your only option. We tested five of the newest generation of 802.11g base stations (also commonly referred to as wireless routers) to see whether their real-world speed and features live up to their "extreme" billing: Apple’s AirPort Extreme Base Station Broadband Edition, Belkin’s 54g Wireless DSL/Cable Gateway Router, Buffalo Technology’s AirStation G54 Wireless Broadband Router, D-Link’s AirPlusXtreme G, and Linksys’s Wireless-G Broadband Router. Although all of these base stations proved to be generally reliable and fast, we found that excellent Mac support and a worthy selection of management features made the Belkin stand out from the rest.

The Setup

All of these base stations make getting up and running relatively easy. Each is backward-compatible with earlier 802.11b equipment, and we had no trouble creating and maintaining a network consisting of both 802.11g and 802.11b equipment using both Macs and PCs. (Each base station includes the option to restrict your network to just 802.11g devices. But while this gives the base stations a slight speed boost, the feature isn’t a part of the standards specification and therefore risks incompatibility with other 802.11g equipment.)

The basic setup process was very straightforward for all the base stations, although some offered a more Mac-centric approach than others. Apple and Belkin, for example, include handy OS X applications that practically automate the setup process. On the downside, because Apple doesn’t offer a Web interface, you won’t be able to manage its base station from a PC. Belkin is more flexible, allowing you to set it up from OS X, Windows, or the Web.

Buffalo, D-Link, and Linksys all rely on a browser interface. While Buffalo can’t set up the Macs on your network for you, its documentation does at least address both OS X and OS 9 client configuration, something that Linksys and D-Link don’t do.

The only glitch we experienced was with the D-Link. When we set up encryption within its setup wizard, repeated attempts generated "404" errors. We solved the problem by leaving the Encryption option disabled and then returning to the feature later within the main management interface.

Speed and Range

With a maximum throughput of 54 Mbps, 802.11g promises a fivefold improvement over 802.11b’s top speed of 11 Mbps. To see what these speeds translate to in the real world, we timed the transfer of a 117MB TIFF file to a 12-inch PowerBook from an Ethernet-equipped Power Mac G4 using OS X file sharing and FTP. Because throughput varied when the same test was repeated, we averaged the scores. We then compared their performance with Netgear’s 802.11b MR-314 Cable/DSL Wireless Router, the winner in our previous roundup (mmmm; July 2002).

All the 802.11g base stations significantly outperformed the Netgear 802.11b base station, which took from three to six times longer in every case to transfer the same file. Of the 802.11g routers, the Belkin proved to be the fastest across the board. It finished the OS X transfer in 46 seconds and the FTP transfer in 1 minute and 9 seconds. The other base stations followed closely behind. The Apple, which was slowest in our file-transfer test and second slowest in our FTP test, proved to be the least consistent in performance; its throughput varied wildly from test to test.

Since throughput degrades significantly as you move away from the base station, we performed our tests with the PowerBook positioned first 7 feet and then 30 feet away from the base station (with two inside walls between it and the PowerBook). At 30 feet, throughput for all base stations decreased significantly -- although not consistently. The Buffalo, the speediest base station at 30 feet, lost just over half its top speed in earlier tests. By contrast, the Apple’s performance was cut fourfold. Throughput for the Belkin, D-Link, and Linksys fell close behind that of the Buffalo.

When it comes to signal range, our tests, with readings taken at 12 feet, 30 feet, and 50 feet, indicate that no particular antenna configuration works best. (Apple and Buffalo enclose their antennas within the case, while Belkin, D-Link, and Linksys each provide a pair of external antennas.) If you need to cover a large area, or if your home or office contains sources of interference, you should choose a base station with a connector for an external antenna, which can extend a range by hundreds of feet. The Buffalo, D-Link, and Linksys -- as well as the $249 Modem Edition of Apple’s AirPort Extreme Base Station -- all offer support for an external antenna, although you’ll have to remove the D-Link’s and the Linksys’s built-in antenna to access it. The Buffalo and Apple (both editions) also offer the ability to bridge base stations, allowing multiple wired networks to communicate wirelessly.

Managing Your Network

For users who want to customize network access and security settings, a good management tool is essential. The Apple and Linksys excel here, with well-organized tabbed screens. The Linksys even offers contextual help when you need it. The Apple offers the unique ability to manage multiple AirPort Base Stations and even apply firmware updates to multiple stations simultaneously from your OS X machine.

Belkin’s screens are attractive and well organized, but the unit’s online help offers only a glossary of terms, with no reference to the base station’s commands or features. While the Buffalo’s interface shows marked improvement over previous products, it still suffers from poor organization and obtuse labeling. On the plus side, each label is accompanied by a link to a help window.

All the base stations we tested provide a NAT (Network Address Translation) firewall to keep unwanted Internet traffic off the local network. The Belkin’s virtual server and applications server features are particularly well implemented, giving gamers and users of other shared applications a quick list of ports that must be opened to the outside world for these shared applications to work.

Schools and businesses can also regulate access to the outside world on all of the base stations by blocking Internet connections from specific local machines. The Belkin, D-Link, and Linksys even let you set a schedule for when those ports can be used. Belkin includes a sophisticated subscription-based parental-control service, while the D-Link can block access to specific URLs and domains.

AOL users who want to share a dial-up AOL account across a network will need to purchase the more expensive Modem Edition of Apple’s AirPort Extreme, which is currently the only base station on the market that does this.

If you need to give wireless Macs access to an AppleTalk printer, you’ll have to look to the Apple, Belkin, or Buffalo, each of which can bridge the AppleTalk protocol between the wired and wireless segments of the network. Apple goes even further with its easy-to-set-up, USB-based print server. While several 802.11b base stations offer a print server, AirPort Extreme is currently the only 802.11g product to come equipped with one. However, the print server relies on Rendezvous, so you can print only via OS X 10.2.

Homeland Security

All the base stations support 64-bit and 128-bit WEP, the flawed encryption technology specified in the 802.11b standard, as well as filters that prevent computers with unknown MAC (Media Access Control) addresses from associating with the base station. The Apple also offers access to RADIUS (Remote Authentication Dial-In User Service), a server-based security scheme used by many large companies, and a unique slider that allows you to turn down its transmission power. This lets you keep more of the Base Station’s signal within your building, preventing passersby from seeing and joining your network, and avoiding access-point conflicts. The Buffalo also stands out by letting you choose from one of three security levels -- low, medium, and high. You can adjust those individual settings later.

Stand Firm

We updated all these base stations during the course of this review. Though firmware upgrade files are largely platform independent, we did run into some browser-related glitches. Belkin’s update couldn’t be applied from Internet Explorer 5.2 under OS X, although Belkin says the upgrade should work with the OS X version of Netscape Navigator. D-Link’s Web site doesn’t provide a link to a Mac OS update, but we were able to use a file listed under "Other" on the site.

Macworld’s Buying Advice

None of these base stations are perfect. For speed, overall ease of use, Mac compatibility, and useful parental-control features, we recommend the $136 Belkin 54g Wireless DSL/Cable Gateway Router, though the difficulties we had with firmware updating concern us. If you want to share an AOL connection, need to use a RADIUS server for authentication, or like the idea of a wireless print server, the AirPort Extreme Base Station will be worth its higher cost ($199, or $249 with a modem and an antenna connector). -- shelly brisbin

Going the Distance with AirPort Extreme

A few users, or a few dozen users, all within a short distance can share a single base station. But trouble occurs when you want to span larger spaces -- such as wide houses, places with thick walls, and offices that occupy more than about 500 to 1,000 square feet -- or support a larger number of simultaneous users.

Apple’s AirPort Extreme Base Station helps with these scenarios. It not only supports more users per Base Station than the original AirPort, but also offers a new bridging feature that lets you avoid adding wires to connect physically separated pods of wired and wireless users.

Working over Large Areas

With earlier versions of AirPort, if you wanted a wireless network with more coverage than a single Base Station could provide, you had to connect all the Base Stations together via Ethernet. In cases where there was no existing wiring or where a physical impediment or gap -- for example, an office located across the street -- intervened, this was inconvenient or impossible.

The AirPort Extreme Base Station offers a unique way out: bridging Base Stations together wirelessly. With this option, previously found only in expensive corporate wireless access points, as many as four satellite Base Stations can be linked wirelessly to a central Base Station, which is in turn connected to the Internet. Each of the bridged Base Stations then acts as a wireless gateway, extending the range of the original. (And, yes, all bridged Base Stations must be AirPort Extreme models; original graphite and snow models won’t work.)

When bridging multiple AirPort Extreme Base Stations, one Base Station serves as the master; the other stations (satellites) bridge only to it. This means that each Base Station has to have a clear signal to the master and be set to the same channel. (You can’t string them out as relays.) This kind of bridging is generally referred to as point-to-multipoint, although Apple’s version is called the Wireless Distribution System (WDS), an industry proposal that has not yet been adopted by others. Each Base Station can operate at up to its full raw 54-Mbps speed when exchanging data with the master.

It’s important to find a good location for each of your bridged Base Stations. You’ll need to test to make sure each satellite can receive a clear signal from the master Base Station. Use a laptop with an AirPort Extreme card and test the optimum location. Remember to keep track of the height at which the laptop rests above the floor: wireless signals don’t travel in a flat plane but in three dimensions, and sometimes the distance from the floor or even the rotation in any direction of a Base Station or card can affect reception. You can get detailed instructions on setting up bridging via AirPort’s Admin Utility from Apple’s Web site (

Supporting Multiple Users

Although home users won’t find themselves with hundreds of people trying to connect to a single Base Station, businesses, especially those that offer some public access, can encounter this situation regularly. The more users you have on a wireless network, the thinner the slice of bandwidth each user gets and the harder a Base Station has to work.

When you install an AirPort network, you need to determine how many users will simultaneously be connected to make sure you have the right number of Base Stations. If one won’t cut it, you can have three or four Base Stations in the same area, each set to a different channel.

So how many Base Stations do you need? Some wireless gateways adver- tise that they support 253 users. But this number is really just a measure of addresses, not of how well the gateway performs. Apple says that as many as 50 users can share a single Base Station at a time, but that’s slicing the bandwidth pie awfully thin. Consider limiting yourself to 10 to 30 users per Base Station to provide the right balance of cost, coverage area, and bandwidth.-- Macworld (US)

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