Troubleshooting Wireless Connectivity

I cannot connect to the WLAN from a wireless station. What should I do?

• Check that the SSID configured on the station matches the ZoneAlarm router's SSID. The SSID is case-sensitive.
• Check that the encryption settings configured on the station (encryption mode and keys) match the ZoneAlarm router's encryption settings.
• If MAC filtering is enabled, verify that the MAC address of all stations is listed in the Network Objects page (see Viewing and Deleting Network Objects).
• Check that the wireless card region matches the access point region.
• Check the wireless card supports the wireless standard that you configured.

How do I test wireless reception?

• Look at the Wireless page, and check for excessive errors or dropped packets.
• Look at the My Computers page, to see information for specific wireless stations, such as the number of transmission errors, and the current reception power of each station.
• On the wireless station, open a command window and type ping my.firewall. If you see a large number of dropped packets, you are experiencing poor reception.

Wireless reception is poor. What should I do?

• Adjust the angle of the antennas, until the reception improves. The antennas radiate horizontally in all directions.
• If both antennas are connected to the ZoneAlarm router, check that the Antenna Selection parameter in the WLAN's advanced settings is set to Automatic (see Manually Configuring a Wireless Network).
• Relocate the ZoneAlarm router to a place with better reception, and avoid obstructions, such as walls and electrical equipment. For example, try mounting the router in a high place with a direct line of sight to the wireless stations.
• Check for interference with nearby electrical equipment, such as microwave ovens and cordless or cellular phones.
• Check the Transmission Power parameter in the WLAN's advanced settings.
• Make sure that you are not using two access points in close proximity and on the same frequency. For minimum interference, channel separation between nearby access points must be at least 25 MHz (5 channels).
• The ZoneAlarm router supports XR (Extended Range) technology. For best range, enable XR mode in the wireless network's advanced settings, and use XR-enabled stations.
• Range outdoors is normally much higher than indoors, depending on environmental conditions.

  Note: You can observe any changes in the wireless reception in the My Computers page. Make sure to refresh the page after making a change.

  Note: Professional companies are available for help in setting up reliable wireless networks, with access to specialized testing equipment and procedures.

There are excessive collisions between wireless stations. What should I do?

If you have many concurrently active wireless stations, there may be collisions between them. Such collisions may be the result of a "hidden node" problem: not all of the stations are within range of each other, and therefore are "hidden" from one another. For example, if station A and station C do not detect each other, but both stations detect and are detected by station B, then both station A and C may attempt to send packets to station B simultaneously. In this case, the packets will collide, and Station B will receive corrupted data.

The solution to this problem lies in the use of the RTS protocol. Before sending a certain size IP packet, a station sends an RTS (Request To Send) packet. If the recipient is not currently receiving packets from another source, it sends back a CTS (Clear To Send) packet, indicating that the station can send the IP packet. Try setting the RTS Threshold parameter in the wireless network's advanced settings to a lower value. This will cause stations to use RTS for smaller IP packets, thus decreasing the likeliness of collisions.

In addition, try setting the Fragmentation Threshold parameter in the wireless network's advanced settings to a lower value. This will cause stations to fragment IP packets of a certain size into smaller packets, thereby reducing the likeliness of collisions and increasing network speed.

I am not getting the full speed. What should I do?

• The actual speed is always less then the theoretical speed, and degrades with distance.
• Read the section about reception problems. Better reception means better speed.
• Check that all your wireless stations support the wireless standard you are using (802.11g or 802.11g Super), and that this standard is enabled in the station software. Transmission speed is determined by the slowest station associated with the access point. For a list of wireless stations that support 802.11g Super, see www.super-ag.com.