I am having issues with wireless client sticking to its existing associated AP until the connection speed drops to 1 Mbps or the client dis-associates. At this point the client goes out to join the AP its closer too. Its a Warehouse environment with Cisco 2602E AP's with 4 x AIR-ANT2524DG-R antennas. The AP's are ceiling mounted some 20 meters high with antennas vertically oriented - contrary to the elevation radiation pattern for this antenna model, I am getting a fairly strong (-58 dbm) signal directly below the AP.
The WLC (5508 running 184.108.40.206) has lower data rates disabled for both 802.11a/n and 802.11b/g/n disabled. No custom RF Profiles are defined. For both 802.11a/n and 802.11b/g/n, the first data rate available is 12 Mbps set to Mandatory. Remaining data rates above 12 mbps are supported. The other RRM, DCA, Coverage Hole, 11n, ClearnAir parameters are at their default values.
While doing active survey (SSID based) using AirMagnet Survey for 2.4 GHz initially, I can see that the client would connect to nearest AP at 54 Mbps. As you walk away from AP the signal strength and the connection data rate would decrease. It won't roam until speed reaches 1 Mbps or client dis-associates. At this point where the connection is 1 Mbps (RSSI < -80dbm, SNR < 15), the client has already passed through coverage area of another closer AP with stronger signal. There seems to be sufficient AP overlap (may be more then required). I was thinking about disabling 12 and 18 Mbps data rates as well to reduce the cell size further. But why is the client data rate going below 12 Mbps when these lower rates are disabled. AP's shouldn't be adv them in its beacon frame and client should roam to another AP when data rate is not good enough. Am I missing something ? How to go about improve client roaming in this scenario ?
What type of client is this ? Does this applicable to different type of client (Apple, Android, laptop,ect.
Unless this is happening to different type of clients it could be the client end issue.
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I am using HP 8470p with two adaptors 1) Built-in Intel Centrino Ultimate-N 6300 AGN and 2) Prixim Wireless 8494 802.11a/b/g/n USB adaptor. Both behave like this. I will probably try using a different notebook / tablet and see if it changes anything. Basically the issue was reported as wireless dropping off on laptops, wifi bar-code readers and voip phones when a user walks around the warehouse. So the issue occurs with multiple device types.
With regards to disabled data rates, are they only relevant on client's first time association to the AP (AP won't let you join unless you use one of them to join) or they also play a role after association (AP won't service an already associated client if data rate goes below lowest available i.e. say 12 Mbps)
I have the same freaking problem. I tried aggressive load balancing , restriction on AP join , bandwidth rate and ccx. All useless.
my situation is a whole class connect to one AP and saturate it but 2 meter away another AP is only servicing 2 people!!!
just so frustrated with this which even opened a case with Cisco tech and they keep asking for debug ! Which i send them and all and all they say update your client driver! (Which they are)
You have to understand that it is the client that decides if it is going to roam (or not). On the wireless network there a just a few things you can do / need to check to help the client making a better decision:
Also make sure that you are running a stable software release on the network and client side, the latest release is not always the better one for your environment.
im trying to understand but just cant!
i have a client which has 6 AP around it and it choose the one which has RSSI of -87 and SNR 13!! Its just wrong even on machine level. Its opposite to what should happen. I can understand a wrong pick but the worst one to pick is just hard to understand
Look at the power levels, channels and data rates configured on all the AP's. Also all the AP's the same model and joined to the same WLC? Clients connecting at that RSSI to me seems like power and data rates can be tweaked.
I too have been struggling with this since we've deployed a Cisco based wireless solution.
Seen better results with the latest Intel drivers. Dell / Broadcom cards are complete garbage in our environment. Also if we use 5 GHz the wireless seems to be more stable than 2.4 Ghz.
Curious as to how to go about some of the responses here. Tuning RRM values? To what exactly (Mine are automatic every 600 sec, Maximum 30, Minimum 11, threshold -70). Also where do you turn on WMM / QBSS?
As far as this being a client side decision, I just don't see why a RFE can't be submitted to Cisco to make it a controller side decision. Basically the controller would keep records of the mac address, and if it tries to associate to an AP you have in a deny list, it would continually send deauth frames to that particular client (like rouge containment), until it associates with an AP you have binded it to (or put in some sort of allow ACL).