New WLAN on Campus: Page 10 of 31

This queued traffic is advertised in a frame at a set interval, along with that ESSID's BSSID (usually the AP's MAC address), to notify applicable devices there may be traffic waiting for them. Broadcast and multicast traffic is sent out in this interval as well. However, in environments with multiple ESSIDs on a single AP--a good practice to help isolate latency-sensitive traffic--PSP devices will be constantly inundated with broadcast and multicast traffic from all SSIDs, negating the benefits of PSP mode and bringing the devices to their electronic knees. The way to fix this is to provision each AP with more than one BSSID so extra SSIDs may use them, and broadcast and multicast traffic won't have the same ill effect.

Symbol's AP, with its ability to have 32 ESSIDs, makes 4 BSSIDs available to mitigate this issue. Airespace and Aruba are the only other vendors to address this.

The Wireless Switch supports 802.1x, as well as Kerberos authentication and WEP encryption. The company says it plans to add support for WPA-TKIP, AES and its proprietary KeyGuard key-rotating algorithm soon.

Setup of the Wireless Switch and APs was painless. After powering on the switch and pushing a configuration policy to the APs, we were ready to test. We were able to evaluate the still-beta 802.11a capabilities available in Symbol's newest AP. Our 11b testing was performed with Symbol's shipping 11b AP.

Symbol's throughout results put it in the middle, with peak 802.11b performance of 5.8 Mbps and peak 802.11a performance of 22.2 Mbps. Interestingly, we found in our 802.11b testing that our notebook equipped with a Symbol NIC achieved better performance than the other NICs, with throughput of 3 Mbps while the others teetered below 1 Mbps. Symbol performed admirably in range tests--tying for first with Airespace and Cisco in 11b range, and placing third in 11a range.