Access Point Scales Up WLANs

Cisco's 802.11b Aironet 1100 series has a long reach but takes considerable setup time.

Cisco Systems Inc.s 2.4GHz 802.11b Aironet 1100 Series access point provides good reach and satisfactory performance on wireless LANs.

In eWeek Labs tests, we configured the $599 Aironet 1100 Series access point to harness VLANs (virtual LANs), quality-of-service markers and Cisco Wireless Security Suite schemes using Ciscos IOS (Internet Operating System) commands, which should be second nature to IT technicians who work with Cisco gear. This is the first time Cisco has implemented its widely used IOS in the Aironet line.

IT managers should consider use of a single access point that provides 802.11b and either the 802.11a or 802.11g standard. The Aironet 1100 has a single radio transmitter that will be field-upgradable to 802.11g in the second half of next year. Once upgraded, 802.11b clients can still get to the access point, albeit at the much lower data rate supported by the standard.

Competitor Intel Corp.s Pro/Wireless 5000 LAN dual access point uses a two-radio approach to provide simultaneous support for 802.11a and 802.11b, which are incompatible with each other.

We got good performance between the Aironet 1100 access point, which shipped in October, and our Cisco Aironet 350 Series WLAN adapter cards. Even at distances of more than 120 feet with two elevator shafts in between, we got 700K bps to 750K bps of throughput while using FTP to transfer a large movie file.

We tested the Aironet 1100 with four wireless clients and configured it to provide equal access to all test clients. The product can also be configured to prioritize throughput: As expected, high-priority clients had data transmission rates similar to those in our first round of tests. During heavy network use, low-priority clients, by design, got less access to the wireless bandwidth.

Rivals in the wireless network space are taking several approaches to beef up WLAN services. Intel is betting on 802.11a and 802.11b combo access points that can coexist with existing network infrastructures. Symbol Technologies Inc. takes a different tack with its Mobius Wireless System, putting the brains for its access points in a centrally managed appliance. The Mobius Axon switch sends power and management configuration to various access points that contain only a radio transmitter and antennae. The costs of both products hover in the same vicinity.

Our tests with the Aironet 1100 showed throughput and reach were more than adequate when compared with other 802.11b WLAN devices. Ciscos decision to make the Aironet 1100 run on IOS is a compelling factor: The product will work with network management and configuration tools that are already in place to handle Cisco switches and routers.

For example, because we already knew how to set up VLANs on Cisco 2900 XL Series switches, it was a snap to implement these features on the Aironet 1100. We could use the command-line interface and configuration scripts to set up our device. We also used the built-in Web server on the Aironet 1100 and the Web interface to make changes to all aspects of the access points operation.

The Aironet 1100 uses SNMP, so we could monitor it using Hewlett-Packard Co.s OpenView Network Node Manager. It was simple to use Telnet to connect to the Aironet 1100 and use familiar commands to make changes to the IP address or access lists that we used to test the various security features on the product.

We used several Cisco Wireless Security Suite tools to control access to the network. Network managers who want to use the Cisco tools—and this ought to be everyone who gets the product—should plan on allocating several hours a day over at least a couple of weeks to test and tune the security system.

Setting up Cisco Aironet security was no more difficult than for other WLAN products weve tested. In fact, it was simple to use the Web-based interface to enter values that defined our security policies. But careful planning and testing are required because, once a security scheme is set up, a lot of hand entry and end-user configuration is required to bring it online.

We created a VLAN at our San Francisco lab facility that allowed guest users to gain access to the Internet but not to our internal testing resources.

IT managers who have VLANs already set up on Cisco switches should have no problem integrating the Aironet 1100 into their current scheme. IT managers with heterogeneous networks will need to set aside several hours of expert configuration time to ensure the Aironet 1100 VLANs work correctly with the non-Cisco equipment.

We did some testing with the proxy mobile IP facility in the access point but did not pursue it extensively because the feature does not work with VLANs. We used proxy mobile IP to roam between Aironet 1100 access points that were connected as roots to our wired network.

IT managers will have to make a trade-off between allowing users to roam with the same IP address and using VLANs. Proxy mobile IP is cool, but we think the benefits of VLANs outweigh the convenience of roaming with the same IP address.

Senior Analyst Cameron Sturdevant can be reached at