we have cisco 5520 wireless controller and 2 different aps : AP1852E and AP1810W
device version is 22.214.171.124 .
we have voice ssid in the campus network
dect phones connected to voice ssid work properly inside the building without any delay or data loss during phone conversations
however , one of the floors in the building is surrounded with glass and the connection fails or conversation failures occur when the user is on this floor
what can be the reason behind this situation
It sounds as though perhaps the wireless signal between the AP and the phone is simply getting attenuated too much, perhaps by the glass.
If the AP's transmit power is much less than the phone's transmit power (typically 14dBm or so), then you can try increasing the AP transmit power and seeing if this helps.
Also, if you have lower data rates disabled (e.g. all rates below 24Mbps turned off), try enabling rates down to 6Mbps.
If you are using 5GHz, then try 2.4GHz, as the lower frequency signal propagates better.
Finally, consider placing one or two APs inside the glass room.
Hope this helps,
If you are using a Cisco wireless phone you can into wireless survey mode and check how much RSSI is inside the room.
For a good coverage for VoWifi you should reach -67 dBm.
You should also consider to use only 5GHz for voice SSID for avoiding any type of interference and channel overlap.
In case that you are using 2,4GHz, as Aaron has suggested you should configure RF Profile for limiting lowest datarates.
Hope this helps
i ran into this fun bug on 8.2.151 at a couple places: CSCvd64819 Cisco Wave 2 AP drops downstream DHCP; kills wcpd (reason: OOM); kernel panic
upgrade. 8.2.166 now should fix it. My issue was that random Aps all WLANs cease to send traffic when roamed to an AP. It may be just most noticeable with the voice traffic in your situation.