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AirPort is a wireless networking protocol from Apple Computer designed for both Macintosh and PC computers. It is based on the IEEE 802.11b (also known as Wi-Fi) standard and has been certified to be compatible with other 802.11b devices. According to Apple, AirPort is capable of speeds up to 11 megabits per second and distances of 150 feet from the base station. The current version support encryption up to 128 bits. AirPort Extreme is the new generation of AirPort, and is based on the IEEE 802.11g specification, and is fully compatible with all 802.11b and 802.11g devices, with speeds up to 54 megabits per second.
AirPort Base Station
An AirPort base station can be used as a fully-featured LAN and/or to connect to the Internet. Some base stations have a modem and all have an Ethernet port (some have two, one for LAN and one for WAN). The AirPort Base Station (models with modem) is the only wireless access point to be officially supported by AOL's dialup service (including phone support from AOL). Some AirPort Extreme base stations also feature a USB port to connect a printer, meaning that that printer can then be seamlessly used as a network device. On the AirPort Extreme this port can also be used to attach a Keyspan USB infrared remote control, to control AirTunes. The newest AirPort Extreme base station also supports Power over Ethernet.
Three generations of AirPort
There have been 3 products from apple whose name is AirPort:
AirPort
AirPort first debuted on July 21 1999 at the Macworld Expo in New York. An AirPort card was sold as an optional accessory with Apple's iBook line of notebooks and the AirPort base station was also introduced. The AirPort allowed transfer rates up to 11 Mbit/s. Antennas were integrated into the displays of iBooks, so reception was very good. Apple was the first manufacturer to embrace 802.11b wireless networking. The AirPort card was later added as an option for almost all of Apple's product line, including PowerBooks, eMacs, iMacs, and Power Macs. Only Xserves do not have an AirPort option. The first AirPort ("graphite') was based on the Lucent WaveLan PC-Card and used an embedded 486 processor. The second ("snow") has a Motorola PowerPC 860.
The original AirPort cards used Lucent's chipset, but unlike the Lucent WaveLan Silver Card (the equivalent 40-bit card) Apple released a firmware update to raise the encryption level to 128-bit (effectively giving a free upgrade to a Lucent WaveLan Gold card) in the spring of 2001. The original AirPort card was discontinued in June, 2004.
AirPort Extreme
On January 7th, 2003, Apple Computer introduced AirPort Extreme, based on the 802.11g specification. AirPort Extreme allows data transfer of up to 54 Mbit/s, and is fully backwards-compatible with the thousands of existing 802.11b (AirPort) base stations in coffee shops, retail stores, offices and homes. All of Apple's current computer models, with the exception of the XServe, have a slot to insert an AirPort Extreme card, and all models of PowerBook and iBook now ship with a card as standard. The Extreme cards, however, do not work in older Macs--the AirPort bus cannot support the new faster transfer rate. However, an AirPort Extreme base station can communicate both with newer 802.11g-based devices and the older 802.11b AirPort cards. The AirPort Extreme runs on an AMD Alchemy Au1500 processor which is based on the MIPS architecture. The original AirPort cards used Lucent's chipset, but unlike the Lucent WaveLan Silver Card (the equivalent 40-bit card from Lucent) Apple released a firmware update to raise the encryption level to 128-bit (effectively giving a free upgrade to a Lucent WaveLan Gold card) in 2001.
AirPort Express
On June 7th, 2004, Apple Computer introduced AirPort Express, based on the 802.11g specification. AirPort Express is an AirPort base station, which currently holds the title of smallest base station in existence, and includes Audio-out, USB for remote printing and ethernet-port. AirPort Express supports AirTunes functionality, which allows audio to be streamed over wireless network to the AirPort Express, which outputs the audio through its audio-out to stereos, for example. AirTunes functionality requires iTunes 4.6, or newer. Audio-out supports digital optical and analog output. AirPort Express can also be used to easily expand wireless coverage via WDS-bridging. The processor in the AirPort Express is not yet known.
Security
In radio based networking, security is a critical aspect since it is possible to access the system from a distant location. As with most WLAN systems, radio network security is based on the Wired Equivalent Privacy standard which gives a number of inherent limitations and is considered by many in the security industry to have been "broken". The latest base stations, beginning with the AirPort Extreme offer also WPA security. More important problems come in the management and default configuration of the Airport. After a reset, the base station enters a fully functional state but defaults to providing no encryption. The system provides for remote management and has a publicly known default1 password.
Even if the management password is securely updated to a secure value, it has been discovered that the management system uses a password which is sent across the network without encryption2. In response to this discovery Apple has stated that management of the Airport should be either by a wired connection or over a WEP encrypted network. Unfortunately, however, the system software gives no warning if the user accidentally, or through ignorance, begins remote management of the AirPort over an insecure network.
The installation manual included in the AirPort Extreme base station includes almost no instructions for security beyond the information on the default password and the location of the security slot which can be used for physically securing the base station using a cable lock. As of 2004 the AirPort web site also lacked obvious instructions or information related to AirPort security, however a the Manual Designing Airport Networks which is available for download there has a chapter devoted to security3. Another manual Managing AirPort Extreme Networks, also available from the support site includes a section on choosing encryption techniques4 and includes a comparison of the different techniques. These sections provide basic security advice, but do not fully cover certain risks; for example, the section on closed networks says that network users "must know the network name", but fails to mention the possibility of guessing.
On the IP networking side, the AirPort is by default configured to provide a NAT gateway and as such, the basic features of a stateful firewall. Whilst this does not provide full application level filtering, it does mean that a computer connected to the Internet through an AirPort base station will be better protected than it would be likely to be with a direct Internet connection.
If used by an experienced administrator with good security knowledge then an AirPort base station can be part of a solution which could provide a level of security acceptable in most applications. In a situation with an inexperienced user setting up a base station with little knowledge of WLAN security, the AirPort system could easily allow the easy configuration of an insecure wireless network with no warnings to the user.
Other meanings of AirPort
AirPort also describes several products including the AirPort base station and AirPort card. AirPort Extreme features bridging, which allows a single Base Station to link with another AirPort Extreme Base Station in order to increase the signal strength (previously, each base station had to be connected to a wired internet line). A software base station for AirPort and AirPort Extreme also exists, meaning that one can turn a computer with a wired internet connection into a wireless network server as long as it has an AirPort card.
The current version of AirPort software is 4.1 (3.1.1 for Mac OS X 10.2). The current firmware version of AirPort Extreme is 5.5. The current firmware version of AirPort Express is 6.1. AirPort software 3.2 or newer include WPA encryption support.
AirPort is most often used in portable computers such as the iBook and PowerBook, though some people use this technology on stationary computers because they find it easier than running wires throughout their house.
References
Airport Extreme Base Station Setup Guide, Apple Computer Inc. Taiwan 1999 Page 20
External links
Category:Apple hardwareCategory:Macintosh internals
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