signal autometic disconnecting after 15 to 20 min, setup " ZD1200, r720 with 802.3at power"

[harekrishna_mon]

while using r720 and ZD1200(ver- 10.1.0.1553) as controller and powering AP's with 802.3at.
the ap's are placed in instute where at a time around 60 students connect to the access point 
But 15- 20 min of using Wi-Fi singnal went after a few seconds it's comming up,
what could be the reason behaind this signal flactuation?,

some info:
we are receiving 18 dBm TX power for the r720  
DHCP server we are using is SOPHOS XG430 ( Checked with diffrent DHCP server as well)

Please help with the same

Thanks,

[sanjay_kumar]

Hi Harekrishna,

Is this happening on all the R720 APs? How many R720 are there in your setup?
After 15-20 minutes of usage, are all the clients not able to see the SSID for few seconds?
Any specific clients (Windows, Android, Apple) are having this issue?
Is this a Open SSID or WPA2?
What is the Inactivity\Session timeout configured on the SSID?

[harekrishna_mon]

there are 9 nos of R720 with all the aps having same problem,
no clients can see the SSID but unable to connect it,
all clients are using Android TAB,
one of SSID is open and another WPA2.
As I haven't change the session timeout, it must be default.
but all the clints are working while this is happening.

[sanjay_kumar]

Hi Harekrishna,

It is best to contact our support team so that they can check the AP logs and assist you on this.

[farzan_qureshi_]

Hi there,
What is the channel bandwidth you are using?
Is auto cell sizing enabled?