Xirrus XS-3900 wireless infrastructure gets good marks overall, with very good marks for management and performance and better than average marks for installation and documentation. The XS-3900 is a wireless switch with 16 discrete access points in a ceiling-mounted housing. The integrated access points (APs) are connected through internal switching to give a 2Gbit/second (full duplex Gigabit Ethernet) transmission vehicle for dense Wi-Fi requirements. Testers found that the XS-3900 appliance will support over 1,000 concurrent users, assuming that they can be spread over a majority of 802.11a-enabled clients/users. The XS-3900 appliance has the appearance of a large smoke alarm with LEDs that give it an outer-space-like quality. There are four concurrent 802.11a/b/g access points (APs) with dedicated channels that are joined to a dozen 802.11a access points (APs) with dedicated channels. There are four large 802.11a/b/g antennas that are overlapped by 90 degrees for more coverage. All can share the same Service Set Identifer (SSID) or have independent ones for each band, for a total of two SSIDs. Two Gigabit Ethernet ports are provided and can be configured for failover. Also included is a 10/100 Ethernet interface for management. The XS-3900 connects to a switch port instead of to an Ethernet hub, which improves availability and load balancing of user streams. A security problem of concern is the fact that, while SSH can be used to manage the appliance, but so can telnet. Testers were not able to turn off telnet access.