This issue is endangering a case of 2000 units of MC3190 and the customer is eager to get our response ASAP, so besides opening a case and waiting for support, I'd like to hear your advice.
Sometimes MC3190 response very slowly while MC3090 running the same application work smoothly. Both Cisco AP and our AP5131 lead to the same result. The customer’s IT said that the cause of that problem is the delay of DNS on MC3190. We captured some packets as attached for your analysis. The first scanning occurred at around 00:00:06. It led to a snappy response. The second one occurred at around 00:05:00, which encountered a delay of about 5 seconds before it got the response from the host. MC3190 was not moving during that test and it never suspended. Fusion version is the latest one, 3.00.2.0.022
All the MC3190 encountered the same problem from time to time on that site. Our partner has checked the wireless coverage and found the signal strength of that whole area is good. The test of pinging the gateway is also ok.
After MC3190 had been idle for about 3-5 minutes, pinging the domain name of their host also caused a delay of 5 seconds, while pinging IP address never suffered any serious delay.
MC3090 with the same application and in the same environment is free of this problem! Fusion is 22.214.171.124.071R.
Wireless infrastructure: cisco-1242ag and 5508. Our AP5131 also tested with the same result.