Matching Wireless Bits in the Alphabet Soup
Selecting the hardware and configuration for your company's wireless network is a complicated and daunting task. A quick sweep of the enterprise router market yields every conceivable feature. As you evaluate the myriad of available options, keep your main goal in mind: to meet your organization’s wireless requirements for mobility and manageability. The most important criteria for purchasing an enterprise wireless router are network standards and speed, security, and dependability.
802.11x Standards and Speed
Whether you’re purchasing a router for a new wireless network or just adding an access point onto an existing network, you need to stay consistent with whichever IEEE 802.11x standard you choose. The standards are 802.11a, 802.11b, 802.11g, and most recently, 802.11n. (For more information about 802.11n, see the sidebar "To n or Not to n: 802.11's Newest Standard Can Potentially Double Your Network Speed.”)
Although the 802.11b and 802.11g standards both operate on the 2.40GHz frequency band, 802.11b was created first and boasts a maximum raw data rate of 11Mbps, whereas 802.11g can move data at 54Mbps and is backward-compatible with existing 802.11b networks. The 802.11a standard also has a maximum raw data rate of 54Mbps, but its transmit range is shorter—802.11a operates on the 5GHz frequency band, which restricts access points to line-of-sight broadcasting. This line-of-sight restriction necessitates more network access points. However, a benefit of using the 802.11a standard is that you get far less interference (e.g., from Bluetooth, microwaves, or amateur radio) on the 5GHz frequency band than on 2.4GHz.
Some vendors claim that their routers are compatible with all four standards. However, your safest bet is to use a consistent network (e.g., 802.11a, 802.11b/g—although mixing standards typically causes performance problems). Note also that your network will never attain a standard’s purely theoretical maximum raw data rate. A much more realistic data transmission measurement that manufacturers provide with each product’s documentation is the net achievable throughput, or NAT. According to the IEEE, each standard’s NAT is about half of its maximum raw data rate.
Security Is How We Get Along: WEP, WPA2, 802.1x, RADIUS, TKIP, VPN, and You
After speed and compatibility, you need to consider security. Enterprise wireless routers offer a wide range of security options, but the selection process can be confusing because different companies often give alternative names to similar functions. In addition, having the right security features is useless unless you configure those features correctly.
All routers manufactured after March 2006 and certified by the Wi-Fi Alliance have both Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access 2 (WPA2) encryption. Because WEP no longer offers sufficient security, you should consider using WPA if you have the option. But if you’re stuck with WEP, you can use several methods to harden its known weaknesses. One method, known as 802.1x, increases authentication security. The 802.1x standard is frequently used in tandem with a Remote Authentication Dial-In User Service (RADIUS) server to further increase authentication security. If your existing wireless network components are compatible, you can purchase a router that uses Temporal Key Integrity Protocol (TKIP) for encryption hardening by encrypting the encryption key itself.
Beyond encryption and authentication, today's enterprise wireless routers offer several types of firewalls with varying degrees of protection. Many routers also support VPN tunnels (i.e., secure conduits for VPN traffic). Each of these security methods has associated network performance hits. Therefore, you need to consider your security decisions carefully to ensure that your network isn’t so hardened that it’s unusable. Unfortunately for the quick-fix junky, the maxim for wireless network security is the same as for security in general: Only proper planning will ensure a secure, robust environment.
Quality of Service
After you determine which security options will enhance your network, you need to decide which dependability features you need. Dependability features are those options that ease your network traffic management and increase your Quality of Service (QoS). As more businesses move to media-rich content such as VoIP solutions, they put tremendous strain on their networks’ bandwidth. Solutions such as repeaters, which strengthen a failing signal, and bridges, which connect a wireless LAN (WLAN) to a hardwired LAN, make a network more robust and are included in many of today's enterprise wireless routers. As you shop for routers, make sure that you aren’t looking at small office/home office (SOHO) routers—which can’t handle the large bandwidth and pervasive signal that enterprise networks require. You also need to consider how many port switches a router can use. The product’s hardware specifications provide this information. Most enterprise wireless routers have four port 10/100 Ethernet switches and an additional DSL or plastic optical fiber (POF) port.
The Bottom Line
Despite all the options available in enterprise wireless routers, you need only focus on three areas: wireless standards and speed, security, and reliability. If you evaluate your environment’s needs and consider whether a router meets your needs in these areas, you’re sure to find the best product for your organization.