Cutting all Cables: Phoneline vs. Wireless Networkingby Eric Hagen on October 30, 2001 4:10 AM EST
- Posted in
- IT Computing
There are several wireless options available today, most using the 2.4GHz range reserved for public use. Of the technologies currently on the market, the IEEE 802.11b standard, occasionally referred to as WiFi is by far the most widely accepted. Developed by the IEEE, it offers a maximum theoretical speed of 11Mbps, which is comparable to 10 Base-T Ethernet but unlike wired networking, it can be completely portable and independent of any wiring infrastructure.
Operating on a Frequency hopping Direct Sequenced Spread Spectrum digital carrier, many manufacturers claim a range of greater than 100m. It should be obvious that any claims for maximum distance are probably assuming line-of-sight transmission, which is rarely the case. Objects such as walls, floors, metal panels, pipes and electrical wiring can greatly decrease this distance.
In situations of low signal strength, the 802.11b standard calls for the adapter to automatically negotiate to lower speed connections to increase reliability. Alternate speeds include 5 Mbps, 2Mbps and 1Mbps. Booster antennas are also available to increase the operating range of any wireless network. With some highly directional antennas, the range of the IEEE 802.11b has been extended beyond 10 miles.
With these types of range capabilities, security is a prime issue for wireless users. The IEEE 802.11b standard offers several built-in levels of encryption. The encryption scheme used by the standard is most generally known as the WEP "Wired Equivalent Privacy" encryption and is offered in 40/64 bit and 128 bit levels.
Don't be fooled by the name, these encryption schemes are mainly effective at stopping casual snoopers but are not strong enough to foil determined hackers. While these encryption schemes are reasonably strong, the 64 bit encryption level can be broken in a matter of minutes and the 128bit level, although a bit stronger, can still be compromised with a bit of effort. Any sensitive data transmitted over these networks should be encrypted as if it were being sent over a public network.
Although these techniques appear to be more exhaustive than any other common network infrastructure, the largest issue is that the network traffic is broadcast over such a large area. The attacker does not need to have physical access to your network, nor does he necessarily even have to be close to the premises if he employs booster antennas. Attackers can take their time cracking your passwords and reading your network data without your knowledge. Unlike conventional attacks via the Internet, no type of firewall can protect wireless computers from being accessed once someone has access to the network.
If network data transmissions are not as big an issue, but you wish to secure your network so that no unauthorized users can log into your systems, there are other standards built into most products. Access control can be secured by MAC address or by a user/password authentication. Again, these are secure only as far as a hacker can not duplicate them. Spoofing MAC addresses is difficult but possible and guessing user's passwords is the oldest hacking technique in the world.
Clearly, making a 100% secure network is not possible, but wireless network administrators with secure data should know the risks and install strong VPN software to protect themselves and their users.