Click to See Complete Forum and Search --> : CRC errors, retransmits, and bears - oh my!


antinym
08-31-2003, 03:20 PM
I have a cisco AP 350 and a workgroup bridge 350 with directional patch antennas about 150' from each other. They are the only devices in this WLAN. aligning the antennas I get signal strength about 40% and quality around 80%. I run VoIP so there's alot of packet transmissions. Unfortunatly I'm getting around 30-70 CRC errors and retransmits a minute. (retransmits are obviously very bad for VoIP). I've changed channels - no help. I'm not sure what else I can do except move to .11a or another technology. Help me!!!

x586
09-04-2003, 11:32 PM
Signal Str seems very low for directional antennas, whats the gain on them ? How long and what type of cable is the patch ?

antinym
09-04-2003, 11:39 PM
the AP has just the four foot cable that comes with the antenna, the bridge has a 20' low loss cable with some cisco part number on it. the gains were at 100mw, but i've played with them as low as 30mw on both sides. - no help. The installation is only about 8' above ground. there's a new traffic signal about 30' to the right of line of sight.

x586
09-05-2003, 01:37 AM
100mw is output power of the device not the gain on the antenna. By default the bridge comes with a 2.2db omni antenna.

1. Try swapping the antenna's
2. Just removing the bridge and hooking the 20' antenna cable directly to a pci wireless nic, just for a test. (I think this will most likely work best)

antinym
09-05-2003, 09:16 AM
Sorry, The gain on the antenna's are 13.5 db

antinym
09-05-2003, 03:50 PM
sorry, 8.5dbi hemispherical patch antenna's.

x586
09-05-2003, 06:51 PM
If you have two 8.5db antenna at 150' with line of sight(even omni antenna) you should be getting 100/100 most of the time.
Is a transformer or some other high power electrical equipent near by, I know you mentioned the traffic light anything else ?

1. Try swapping the antenna's
2. Remove the bridge and hooking the 20' antenna cable directly to a pci wireless nic, just for a test. (I think this will most likely work best).