Lots of RX CRC ERRORS with REALTEK PCI card

Interference, multipath, reflections, co-channel users, cordless phone, microwave oven, X10 TV remote, wireless TIVO, wireless rabbit, WiMax, Frequency Hopping Spread Spectrum radios, HomeRF, Bluetooth, Zigbee, Proxim Lynx, burglar alarm doppler, 2.4GHz wireless keyboard, harmonics of CPU noise, magnetic field pickup from transformer or flyback, power supply noise, RF lighting, noisy wall wart, 2.4Ghz ham radio operation, and whatever else I forgot.

Try changing access point channels (1, 6 or 11) and see if it helps.

Jeff

Thanks yet again. In your experience have you seen such a high level of RX Errors and for the link to still function ? Is it quite acceptable for this level in your experience or would you definitely want to tweak some settings to reduce it ?

Jeff

I changed the channel to channel 1 and RX CRC ERRORS all but disappeared. I am waiting for some RangeLAN PC Cards I bought from the US to arrive so I can have a look at the competing frequencies in my area. That was also thanks to a tip from you.

Thanks again

It depends on the cause. A wired ethernet connection will typically have about 1-5% errors caused by collisions. My dedicated wireless bridge links typically run about 3-5% with ocassional very short term excursions as high as 30% caused by microwave ovens. I have a marginal cross town link that runs about 15% average and getting worse by the month. You're apparently running at 50% or higher error rate, which is totally unacceptable.

CRC errors are basically corrupted packets arriving at the receive end. The sources can be numerous, complex, and mutual interactive. In some cases, the radio link can cause these errors in its heroic attempt to maximize transmission speed or deal with a bottleneck (i.e. sending more data than the link can handle). Since you've supplied absolutely zero detail as to what you're doing, where the numbers are coming from, and with what hardware, I won't speculate as to the cause or nature of the packet loss.

However, I can suggest that you consider a few tweaks which may help.

1. Turn on CTS/RTS flow.
2. Lower the fragmentation threshold so that you are sending smaller packets with a higher probability of arriving.
3. Fix the data rate to the slowest OFDM speed (6Mbits/sec) to improve receive sensitivity.
4. Improve the path by using larger antennas to increase fade margin.
5. Use directional antennas to reduce interference pickup from the sides (but not inline).
6. Monitor and graph using SNMP and MRTG to get a feel for the extent, time, and severity of any interference, atmospherics, or path problems.

ive just noted down those 6 tips in my handbook,.

thanks again.