Wireless Troubleshooting

Transcription

1 Wireless Troubleshooting Applicable Version: onwards Applicable Models: All WiFi Models - CR15wi, CR15wiNG, CR25wi, CR25wiNG, CR35wi, CR35wiNG Connectivity Issues with Cyberoam Inbuilt Access points 1. Check the Wireless Network Adapter Make sure your adapter software and drivers are of the latest version. Check from the Internet and update the wireless adapter software and drivers. 2. Check Wireless Client Standards Clients working on a standards may not connect to Cyberoam due to interoperability issues. Cyberoam supports the following standards: n (5 GHz Band) b (2.4-GHz Band) g (2.4-GHz Band) WEP64 and WEP128 Wired Equivalent Privacy (WEP) Wi-Fi Protected Access (WPA), WPA2 and WPA2 Auto using pre-shared keys The reason for the same is a Clients are not interoperable with b/g/n standards. 3. Channel and International Compatibility Different a/b/g/n standards are followed in different countries. The channels that are available for use in a particular country differ according to the regulations of that country. Hence, make sure that you set the correct location of where the Appliance is placed. To set the location logon to the Web Admin Console, go to Network > Wireless LAN > Settings and set the Geography according to country or location. Example: If you are in United States, change the geography to make sure Cyberoam changes the channels accordingly.

2 4. Authentication and Encryption Your Wireless Clients should support all the authentication and encryption modes defined on Cyberoam. Note: Windows XP Service Pack 2 doesn t have built-in support for WPA/WPA2 and requires updating a patch or need to use the Adapters Wireless utility to enable the support. 5. Adjust the Transmit Power Check the Transmission Power of Cyberoam Access Point. Your Wireless client should receive the maximum signal from the Cyberoam. Higher the number, larger the area the Wireless Client will broadcast. To adjust the Transmission Power, go to Network > Wireless LAN > Settings and select the power level of Radio Signal Transmission. For example, if you want signal to go from building-to-building, select Full Power and if you want to keep the wireless signal to a small area, select minimum. Available Options: Full Power Half (-3dB) Quarter(-6dB) Eighth(-9dB) Minimum 6. More than One Access Point Roaming Aggressiveness A wireless device can "roam" from one access point to another, with the software and hardware maintaining a steady network connection by monitoring the signal strength from in-range access points and locking on to the one with the best quality. If there is more than one wireless network that you normally connect to in the vicinity of the Cyberoam Access Point. Make sure your wireless adapter has a low Roaming Aggressiveness. If this setting is on the higher side it might cause the adapter to flap between SSIDs.

3 Example: A user can move from Area 1 to Area 2 transparently. The Wireless networking hardware automatically swaps to the Access Point with the best signal. To set the Roaming Aggressiveness in Windows, go to Network connections. Right click on the Wireless adapter, click on Properties > Configure > Advanced to set the Roaming Aggressiveness Value. 7. Stop DHCP Service Stop DHCP Service on Cyberoam so that it does not collide with the internal network's DHCP Server. In case of any issues while connecting to the Wireless, define a DHCP scope for the Wireless Interface. 8. Change Your Wireless Channel If other wireless networks are present in the vicinity of Cyberoam Access Point, there is a good chance for an interference of the wireless networks, which might cause severe connectivity and low throughput issues. When you set the channel to "Auto", Cyberoam picks the best channel which has least interference. In general channels 1, 6, 9, 11 will have lease interference.

4 9. Distance Check the distance between the Cyberoam access point and the wireless client. If user sits near the wireless router/access point, he/she will get good network speed. However if another person joins the network sitting far from the wireless router/access point, the network speed of both computers will be dropped drastically. The rule is the further your location from the wireless router/access point, the slower your connection will be, and the distance will affect the network speed of other users too. 10. Wireless Utility Many new Wireless Laptops and Wireless ready Desktops come with a configuration that loads the Original Wireless manufacturer s Utility at Startup. The Wireless connection can be maintained only by one agent; as a result most of these utilities are programmed to switch Off Windows Zero Configuration (WZC). Many people prefer the flexibility of WZC. In such a case, the 3rd party Utility has to be disabled from the beginning, and WZC has to be initiated again. It is important that the Wireless should be managed only with one application. You can use the Original Utility, or WZC. When one is used the other has to be Off (Not loaded into memory, and not maintained as active Windows service). 11. Broadcast SSID The access point is identified by its SSID. Users who want to use the wireless network must configure their computers with this SSID. Broadcasting the SSID enables clients to connect to your wireless network without knowing the SSID. If this option is not enabled on Cyberoam Web Admin Console, then you may not be able to see the wireless SSID when you scan for the wireless networks on your Wireless Client. Go to Network > Wireless LAN > Access Point, select the Access Point and Enable to broadcast the SSID.

5 12. Interference from Wireless Signals Install the Cyberoam wireless access point at least 1 m (3 feet) away from other appliances that send wireless signals in the same frequency range. Such appliances include some microwave ovens, cordless telephones, baby monitors etc. Any appliance that transmits in the same general range as b or g (2.4 GHz) can generate interference. Throughput Issues with Cyberoam Inbuilt Access points/wireless 1. Channel/Frequency Select the channel you wish to use on your wireless LAN. The wireless channel in use will be between 1 and 11. Setting the channel with least interference is crucial to maintain good wireless connectivity and throughput. 2. Transmit Power Transmit power plays an important role to make sure that the wireless client receives good wireless signal from the wireless clients. Too low transmit power cannot provide enough signal to the client and cannot provide the desired throughput to the client. Also, there are chances that high transmission power will lead to high interferences. 3. Throughput Throughput of Wireless and LAN are not comparable. Wireless RF radio is always half duplex in nature and many other factors are taken into consideration while checking the wireless throughput. This factor may also effect the communication between 2 wireless clients connected to the Cyberoam wireless Radio. 4. Encryption Throughput on the wireless depends on the encryption levels on Cyberoam. It is always advisable to use Advanced Encryption Standard (AES) encryption over Temporal Key Integrity Protocol (TKIP) when using WPA/WPA 2 security on the wireless. The reason for the same is AES being a hardware based encryption mechanism require less CPU cycles than TKIP which is software based encryption. Using AES improves the throughput of the wireless Radio. 5. Support Same Standards Throughput when the access point is using a/b/g/n mixed mode will always be less than when you are using dedicated b, g, and n modes. Make sure that the wireless clients support the same standards when you configure these settings. 6. Advanced Settings Check if the Beacon interval is set to a value higher than 100ms. Cyberoam, by default, sets the value to 100ms (Lower the value higher the throughput) Reduce the Fragmentation and Request To Send (RTS) threshold to 2304 from After making these changes there will be a significant improvement of throughput in the wireless Radio. 7. Bandwidth Management Rules No bandwidth management rule has been setup for Access rules from Wireless Zone to WAN Zone. Document Version: March, 2015