The blanket approach to implementing wireless networks in businesses is proving to be an interesting alternative to traditional solutions as it doesn’t require any cell planning and is designed to provide seamless roaming. Every access point uses the same radio channel, and connections are controlled by the switch.
Zyxel’s NXC-8160 aims to put a wireless blanket on the ground by allowing lightweight access points (APs) to be deployed wherever needed and managed easily from a single location.
This solution is the result of Zyxel’s recent agreement with Extricom and aims to allow wireless networks to handle a range of services such as voice and video that have often been problematic. At its foundation is the NXC-8160 appliance which provides an octet of 802.3af PoE compliant ports used to drive Zyxel’s NWA-8500 lightweight access points which incorporate separate 802.11b/g and 802.11a radios.
The APs are completely different to conventional lightweight APs as they don’t even have a MAC or IP address. They merely provide a radio link for the client who is essentially associating with the appliance and not a specific AP. Consequently, they are easier to deploy and aim to provide overlapping channels allowing mobile clients to move from one to another with no loss of service.
Bear in mind that as the APs are almost completely dumb they cannot identify and contain rogue APs or wireless clients – abilities offered by products such as Cisco’s Wireless LAN Controller or Netgear’s new ProSafe Smart Switch solutions. The other feature conspicuous by its absence is any decent monitoring facilities. The appliance does provide Syslog services but the information forthcoming is minimal. Using the Kiwi Windows Syslog server we could ascertain how many wireless clients were connected and their MAC addresses but that was all.
We found installation extremely easy as we set up the appliance in our lab and placed one AP in the same room plus two more in other office locations around fifty metres away. To provide general network services to our wireless clients we made available a Windows Server 2003 R2 domain controller which provided Internet and LAN access.
The appliance’s web interface opens with a status report on the LAN port, the two radios and all PoE ports showing which ones have APs attached. Wireless configuration is basically a two-step process where you first decide how each radio will function and for each one you can select from 802.11a, b, g or mixed b/g operations. You also pick the channel to be used, decide on the data rates it will support and whether it can use rate adaptation.
Now you move to SSID creation where you associate a radio and decide on an encryption scheme which can comprise WEP or WPA/WPA2 and RADIUS server authentication. This makes the NXC-8160 quite versatile as you can advertise multiple SSIDs offering a variety of radio services and encryption schemes.
Also, for each SSID you can enable masking, decide whether intra-BSS traffic is allowed and assign VLAN memberships. If you want more than eight APs you can add up to five more appliances and manage them centrally by designating one as master which securely communicates with the others and provides them with all configuration details.
To test the roaming capabilities we used a Fujitsu Siemens laptop fitted with a standard TrendNet 802.11n wireless PC Card and associated it with an SSID configured with an 802.11g radio and WPA-PSK. As soon as we connected we were able to access our Internet and LAN services without any problems. To test connectivity we set up a simple continuous Ping with our domain controller and then took the laptop for a walk through the building. We saw signal strength drop to around 25 per cent as we reached the mid-point between APs and as we continued it simply increased in strength as we moved closer to the next one. The laptop client software was totally unaware of the AP change and the worst we saw with the Ping test at any time during our travels was two timeouts as it swapped to the next AP.
Zyxel’s wireless blanket will make you warm and cosy with its ease of deployment and good roaming capabilities but the high price is a drawback. We found it worked well enough in the lab but we would have expected far better monitoring facilities for our money as they are almost non-existent.
Zyxel’s blanket certainly looks an effective alternative to the traditional wireless network deployment solutions but it is comparatively expensive and the monitoring facilities need to be much better at this price.