Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Cisco 350 Throughput Problem

Hi Everyone!

Lately, I have been having an annoying problem with my Cisco 350 Access Point and PC-Card. Everytime, data is being transferred over the wireless connection, the speed drops down to 2Mbps and recovers to 11Mbps, when the data is no longer being sent.

This happens independently of the relative position of the devices, with the signal strength at 100% and Signal Quality at 75%.

A reinstallation of winXP did not improve the situation, neither did upgrading both devices to the newest firmware, or using Win2000 on a different computer.

I would be grateful for any pointers that would help me solve this problem.

Regards, Igor Testen

Cisco Employee

Re: Cisco 350 Throughput Problem

Hi Igor,

Do you see a lot of CRC errors on either the client or AP or both ???

Most throughput issues in WLAN are due to interference, CRC error often point to interference.

Try a new channel also what version of firmware is on the AP ?

New Member

Re: Cisco 350 Throughput Problem


Thanks for helping me. The client reports 21,418 PLCP CRC Errors and 14216 MAC CRC Errors, within 4,5 hours of up time and 17Mb Transmitted.

Does that qualify as "a lot"? The firmware on the AP is 12.03T. I've gone through all the channels, but without much luck. I have the feeling that around channels 6, there the fewest of the above CRC errors per minute.

Regards. Igor

Cisco Employee

Re: Cisco 350 Throughput Problem


The CRC errors of interest are the MAC ones.

The counters are incremental from boot up or the last clearing so the raw data like that is not that useful

You need to look at the rate of incrementing on the errors compare to the rate of traffic at the time

crc errors can come in a burst sometimes

What did your site survey show up when you did it in respect to channel utilization and noise along with possible sources of interference

CreatePlease login to create content