Yesterday we spend all day debugging our network as we had strange "outages" of 1-3 seconds on our Comcast Netgear CG3000DCR router with Firmware version V3.01.05.
It turns out that our software sends a UPnP M-SEARCH broadcast on the network with an MX of 5 (according to the UPnP specs a devices should respond with a unicast UDP package between 0 and 5 seconds).
The Netgear router IS responding in 0-5 seconds but instead of continuing to process other requests on the network, it STOP ALL PROCESSING and halts all traffic for that time!
This can be even seen when a user hits "Refresh" in the "Network" section of Windows Explorer. Windows sends an M-SEARCH with a MX of 3. This causes the router to "only" pause processing between 0 and 2 seconds but its still noticable when pinging the router.
an MX of 1 or zero does not cause the router to pause as it immediately responds to the M-SEARCH request.
Is there a later firmware that fixes this problem?
I do know that the SMC and the Cisco Router do NOT show this behavior.