Motorola MC9090 handhelds and 7363 Access Points with Zone Director

[michael_daracz]

I have 4 motorola handheld guns roaming between 6 overlapping 7363 access points with Zone Director 1100. The guns are running a simple wavelink telnet application. They are sitting on a separate open WLAN with no authenticaion but with an MAC ACL. Intermittently, the guns are having problems re-establishing a link to the access point(bars that indicate signal strength go from full to none, and the handheld indicates that it lost connection with the server), even though they are within the range of them. It doesn't happen often but its annoying enough. It usually takes 10 - 20 seconds to re establish a link. What settings should I check? Thank you!

I

[Eddie_Felmer]

The things to try are:
- Enable OFDM only and set BSS Min Rate = 12 on the device WLAN
- Upgrade to one of the version Michael mentions with some loop fixes
- Try setting a higher DTIM value on the APs for the device WLAN (seems 5 is recommended for Moto devices). This is currently a bit painful as you can't do it via the ZD WebUI so have to CLI to every AP and check you are applying it to the correct WLAN (if you only have 1 WLAN then its designator will be the same on every AP so you could do it with the ZD CLI remote_ap_cli command)
- Enable RTS-CTS protection on the WLAN

[dominic_simpson]

Thanks Eddie, I will give this ago. I just need some info how to setup the following:

-Enable ODFM
-Enable RTS-CTS

I'm assuming that I would be able to use the following command to set the DTIM on the ZD CLI: remote_ap_cli –A “set dtim-period wlan2 1”

Where wlan2 is my wlan that all handhelds are connect on and the number 1 represents the DTIM setting I want which in my case would be 5?

Thanks,
Julius

[julius_kisieli1]

Thanks Eddie, I will give this ago. I just need some info how to setup the following:

-Enable ODFM
-Enable RTS-CTS

I'm assuming that I would be able to use the following command to set the DTIM on the ZD CLI: remote_ap_cli –A “set dtim-period wlan2 1”

Where wlan2 is my wlan that all handhelds are connect on and the number 1 represents the DTIM setting I want which in my case would be 5?

Thanks,
Julius

[primoz_marinsek]

Enable OFDM-only (per WLAN)

set ofdm-only : set ofdm-only {enable|disable}
-- Enable/Disable OFDM-only mode (exclude 11b CCK rates)

Sure hope RW will make it a global feature, not just per WLAN

About enabling RTS-CTS, I'm not too shure, but I think it's this

set rts-thr : set rts-thr {disable|}
-- Modify Request to Send threshold

You need to set a threshold. I would set it at size just below what your handhelds are sending data at so it will kick in.

[Eddie_Felmer]

You can enable OFDM only and configure the bss min rate in the ZD CLI per WLAN, rather than having to do it on the AP using set commands:
Login to ZD CLI - "en"able mode - "config" mode - "wlan xxx" (wlan name is case sensitive)
"ofdm-only"
"bss-minrate 12"
"end"
"show wlan" to show the configuration is set.

In relation to remote_ap_cli –A “set dtim-period wlan2 1” that looks correct (with a 5 in your case). The only issue is that depending on how the APs are provisioned with WLANs (maybe different WLAN on different AP, provisioning order) they won't all necessarily be called wlan2. Note this is not the wlan name you give the wlan, but an internal wlan identifier - 2.4Ghz start at wlan0 and 5Ghz start at wlan32 (on later code releases). You can get get the wlan name-SSID mapping using "get ssid wlanx" i.e.
rkscli: get ssid wlan0
wlan0 SSID: Test
This way you will find what wlan name to use for each AP (if you are lucky it might be the same for all APs!).

In relation to RTS-CTS as Primož says its "set rts-thr {disable|}". Again you will need to know the correct wlan identifier. Generally the advice is to set the threshold to a size larger than max single frame size as you probably don't want RTS-CTS for all packets, just the larger ones that will use more airtime. In 11g the recommendation was 2346, but since 11n aggregation it supports up to 65535. I would change the other settings first, monitor and if still having issues then try RTS-CTS at 2340.