Q4: What is the default IP for the ISPAIR CPE Series?
A: The Default IP is 192.168.1.3
Q5: What is the Default Password for the ISPAIR CPE Series?
A: The default password is "admin" (without quotes).
Q6: Does the ISPAIR CPE support Web Interface?
A: Yes, the ISPAIR CPE has a basic Web GUI (Graphical User Interface). Take a look into the Quick Configuration Guide for further information.
Note: Advanced features such as Firewall or NAT are only available through the Netkrom NMS.
Q7: What are some reasons why the ISPAIR CPE is not making a wireless link?
• Check the output power of the
- don’t leave it at default values and test different values. Make sure Diversity is disabled.
•; Check the signal from the client as well as going to the client site. Is it an acceptable level? A good signal level can be considered from -75 dBm to -55 dBm and above.
•; If your AP is managed by the Netkrom NMS as well, you should check the fade margin of your clients under the Association List Button. A good wireless link have a Fade Margin higher than 20
•; Check if you have a clear Fresnel Zone between the AP and the Client
Q8: How am I able to configure the ISPAIR CPE?
A: Available methods to configure the ISPAIR CPE:
• Netkrom NMS.
• Web GUI.
Q9: How do you supply power to the ISPAIR CPE?
A: The ISPAIR CPE includes an IEEE 802.3af PoE injector - 110/220VAC to 48VDC, 350mA
Q10: Can my ISPAIR CPE act as a bridge and bridge two networks transparently?
A: Yes, the ISPAIR CPE can easily bridge two networks. Follow the example below to make your radio work as a bridge.
Notice that Wireless Interfaces (athx) are disabled by default.
Remember that in bridge scenarios, the subnet of local network and remote network must match.
Notice that after system reboot, the bridge will be the only interface having an IP address
Q11: Can my ISPAIR CPE act as a router?
A: Yes, the ISPAIR CPE can act as a router as long as there is not a bridge including all physical interfaces (ethx, athx - enabled).
of the ISPAIR CPE
which only has two
physical interfaces (eth0 and ath0). the only way to make it work as a router is setting up different subnets in each interface without creating any bridge.
The same way as a LAN router works, physical interfaces must be on different subnets; otherwise the ISPAIR CPE may become unstable.
Q12: How do I configure the Wireless Settings of the ISPAIR CPE?
A: Follow the example below to configure the Wireless settings of the ISPAIR CPE, which is configured in AP mode under IEEE Standard 802.11b/g (2.4 GHz) due to the MiniPCI module (ath0) being configured supports that Frequency Band.
Q13: Can my ISPAIR CPE be used with encryption?
A: Yes, the ISPAIR CPE supports WEP 64/128 and WPA, WPA2 with TKIP & AES ciphers.
Q14: What frequency does the ISPAIR CPE support?
A:The ISPAIR CPE depending of the Model Name can cover the following Frequency Bands:
• ISP-CPE500Gx: IEEE 802.11 b/g Unlicensed Band 2.4 GHz.
2.3 to 2.7 GHz MMDS Licensed Band.
• ISP-CPE510G: IEEE 802.11 b/g Unlicensed Band 2.4 GHz.
• ISP-CPE500Ax: IEEE 802.11 a Unlicensed Band 5 GHz.
4.9 GHz Public Safety Band.
• ISP-CPE510A: IEEE 802.11 a Unlicensed Band 5 GHz
• ISP-CPE900: 900MHZ Non Line of Sight Unlicensed Band (902 - 928MHz)
• ISP-CPE350: 3.4 to 3.7 Ghz Band
Q15: Does the ISPAIR CPE support MAC based authentication?
A: Yes, the Netkrom NMS has what is called an "access control list"; this list is what you would use to accomplish the MAC based authentication.
Q16: I can see the link light on the switch from the
ISPAIR CPE, but I can’t log in, why?
A: The most likely reason you can’t log into is because your network card isn’t set up on the correct subnet. So you’ll need to change the IP address of your laptop within the same subnet.
e.g. The default IP address of the ISPAIR CPE is 192.168.1.3 / 24. In order to configure the unit you must configure in your PC an IP address 192.168.1.100 / 24 for instance.
How do you reset the ISPAIR CPE to default configurations?
In case you forgot either the IP address or the administration password of the ISPAIR CPE you have to reset the radio to factory default settings using the reset button located in the mainboard of the unit. Proceed as it is explained below:
Turn on the radio
Wait for only 5 seconds since you turned on the radio and press the reset button
Keep holding the reset button for 15 seconds
After this, DIAG LED will blink fast. Release the button
Power cycle the radio
Q18: How can I detect RF Interference in my wireless link?
A: The Netkrom NMS through the Site Survey feature can detect the number of APs and the channels being used by them around your Wireless Link. Try using other available and non-overlapping channels.
Q19: What is the recommended separation between two antennas placed in the same tower or pole?
A: The minimum distance recommended is 2 meters. This separation has to be done vertically and horizontally.
Q20: What are possible sources of interference for the radio frequency (RF) link of the
A: Interference can come from a number of sources, such as:
• 2.4 GHz cordless phones. (In case of 802.11b/g radios).
• Improperly shielded microwave ovens. (In case of 802.11b/g radios).
• Wireless equipment that other companies manufacture
• Electrical motors and the moving metal parts of machinery can also cause interference
RF interference is one of the main causes for poor connection. Interference can be caused by adjacent 802.11 networks or other sources, such as Microwave ovens or cordless phones that operate in the same frequency. Interference caused by adjacent 802.11 networks is of two types:
Co-channel interference: When access points, whose coverage area overlaps, are configured in the same channel or channels with overlapping frequencies, it causes connectivity issues for clients in the overlapping coverage area. In order to avoid this issue, either change the channel number to a non-overlapping channel, or move the access point farther away so that their coverage areas do not overlap. For example, in 802.11b/g, network channels 1, 6, and 11 are non-overlapping channels
Adjacent Channel interference: When access points are placed too close to each other or use high output power levels, it causes interference, even when the access points are configured on the non-overlapping channels. Decrease the power of the access point to fix this issue.
Note: Non-overlapping channels are also called adjacent channels, which explain the name adjacent channel interference.
Use spectrum analyzers to locate interference sources, such as microwave ovens or cordless phones that operate in the 2.4 GHz range, or devices that operate in the 5 GHz range. Remove the interference sources once they are identified. Alternatively, you can change the standard on which your wireless networking operates, for example, from 802.11b/g to 802.11a to avoid interference.
Another important aspect for effective RF communication is signal strength. Poor signal strength leads to intermittent connection. Obstacles, such as walls, metals, absorb and reflect RF energy, which reduces the signal strength. Increase the power to the required level on the access point to provide the adequate coverage. You can also use high gain antennas to extend the range and the signal strength, but ensure that it is FCC approved to operate with the device.
Note: Signal to Noise Ratio (SNR), which is the difference between the signal strength and the RF noise (RF signal or energy from other sources that operates in the same frequency as the wireless network), is a key factor to measure the quality of the link. Higher SNR indicates a good link quality, which results in faster data transfer. A lower value indicates poor quality, which leads to intermittent connectivity or poor performance. Wireless Packet analyzers/site survey software can show you the SNR and throughput at a particular location.
Radio Frequency Interference (RFI) involves the presence of unwanted interfering RF signals that disrupt the original data signals from wireless devices. RFI in a wireless network can lead to adverse effects, for example, intermittent connectivity loss, poor throughput, and low data rates. There are different types of RFI that can occur in a wireless network environment, and you must tale these RFI types into consideration before you implement wireless networks. RFI types include narrowband RFI, all-band RFI, and RFI due to adverse weather conditions.
Narrowband RFI—Narrowband signals, depending on the frequency and signal strength, can intermittently interrupt or even disrupt RF signals from a spreadspectrum device, such as a wireless radio. The best way to overcome narrowband RFI is to identify the source of the RF signal. You can use Spectrum analyzers to identify the source of the RF signal.
Spectrum analyzers are devices that you can use to identify and measure the strength of interfering RF signals. When you identify the source, you can either remove the source to eliminate RFI, or shield the source properly. Narrowband signals do not disrupt original data RF signals (from a wireless radio) across the entire RF band. Therefore, you can also choose an alternate channel for the radio where no narrowband RF interference occurs. For example, if unwanted RF signals disrupt one channel, say channel 11, you can configure the wireless radio to use another channel, say channel 3, where there is no narrowband RFI
All-band RFI—As the name suggests, all-band interference involves any unwanted RF signal that interferes with the data RF signal across the entire RF band. All-band RFI can be defined as the interference that covers the whole spectrum that the radio uses. The entire RF band does not point to the ISM band alone. The RF band covers any band of frequencies that the wireless radios use.
A possible source of all-band interference that you can find commonly is a microwave oven. When all-band interference is present, the best possible solution is to use a different technology, for example, move from 802.11b to 802.11a (which uses the 5Ghz band). Also, the whole spectrum that the radio uses is 83.5 MHz in FHSS (the whole ISM band), while for DSSS it is only 20 MHz (one of the sub-bands). The chances of an interference that covers a range of 20 MHz are greater than the chances of an interference that covers 83.5 MHz. If you cannot change technologies, try to find and eliminate the source of the all-band interference. However, this solution can be difficult, because you have to analyze the entire spectrum to track the source of the interference.
RFI Due to Adverse Weather Conditions—Severely adverse weather conditions, for example, extreme wind, fog, or smog can affect the performance of wireless radios, and lead to intermittent connectivity issues. In these situations, you can use a radome to protect an antenna from the environmental effects. Antennas that do not have radome protection are vulnerable to environmental effects, and can cause degradation to the performance of the radios. A common problem that can occur if you do not use the radome is the one due to rain. Raindrops can accumulate on the antenna and affect performance. Radomes also protect an antenna from falling objects, such as ice that falls from an overhead tree.