One Way intermittent network connectivity issues, ssh connections, video calls

Hi all,

I know it is Sunday; but I see almost 1000 people online :) Thank you for being here. I always visit subs and see if anyone needs help. I need an urgent help with our network, please let me know what I am missing. Our network environment details are as follows.

We are a public school with 3 Locations. Location 1 gets 1Gbps from our ISP and we have point-to-point connections to other locations. Each location is connected with Layer 3 switches.

We have a Cisco ASA5516 Firewall running ASA Version 9.6(1) with Firepower and connecting to our ISP with 1Gbps. Iboss was on the next chain but we disconnected iboss completely while trying troubleshoot this issue. The firewall and iboss filter is at Location 1, the next hardware is C3850 Layer 3 Switch connecting to Location 2(C9300) and 3(C3850). All Locations have Layer 2 2960 distribution switches. Location 1 has Cisco 5520 Wireless Controller connecting to Location APs(AIR-AP1852 and AIR-CAP3702I). Firewall traffic usage looks way under 1Gbps. I setup PRTG Network Monitor and all devices look perfectly fine.

I tried to gather as much detail as possible before posting here. So here is the situation: When we have Zoom calls on our Wifi network, the connection would hang and we can't hear/see(would be frozen) the other side but they can hear/see us.

We setup a Zoom call with about 10 computers and we have experienced a problem with Zoom once or twice. We had a laptop connected our wired network and the zoom call was not hanging there. I am not sure how ssh connections are related but I tried connecting our AWS servers just to make an ssh connection. I used the following script to make continuous connections.

while true; do msg=$(ssh ubuntu@production.domain.org date) && echo $msg && echo $msg >> a.txt; done 

The ssh connections were not causing zoom calls to hang all the time, but when ssh connections were run and hanged the Zoom calls were getting hanged too.

Things I did not test yet:

• I did not try doing ssh connections on a wired network and see if the devices on wired/wireless network had problems with zoom.