Multicast (and broadcast, which 802.11 treats like a special case of multicast) is very expensive on Wi-Fi networks, because multicast packets aren't Acked (because it would be an Ack storm), so the packets have to be sent at a lowest-common-denominator packet rate that everyone on the network can reliably receive, and that means that it's quite often the lowest data rate the band can handle, which for 2.4GHz is the old 1Mbps rate from 802.11-1997 (predates even 802.11b).
Given that, combined with Wi-Fi's natural inefficiencies, it means that even 500kbps of multicast traffic can use up all the airtime of a poorly-designed 2.4GHz Wi-Fi network.
If your AP lets you set the multicast rate it uses, set it up to something higher. Preferably around twice the rate of all multicast/broadcast traffic on your network. That is, the data rate of your video multicast, plus the mean aggregate data rate of things like Bonjour, UPnP, NetBIOS Name Service, ARP, DHCP, etc. Honestly the video multicast probably dwarfs the background traffic.
Beware that if you have some devices that you like to use at locations that happen to be at the edge of their range, where they can only get the 1Mbps data rate reliably, you'll end up making them unreliable in those locations. ARP is fundamental to a properly working LAN, and ARP uses broadcasts.
If you set the multicast rate to something other than 1, 2, 5.5 or 11Mbps, you'll be excluding 802.11b clients from your network. So to allow selection of other rates, some APs require that you explicitly disable 802.11b compatibility mode (i.e. set it to G/N mode, or G-only, or N-only).
Some good APs have an option for "IGMP Snooping", which you should probably enable. It's a way for an AP to keep from forwarding certain kinds of multicasts (especially audio or video streams) to the wireless network if no devices on the wireless network are trying to view those multicasts. Just be sure not to run your camera-watching software on any machines that are using wireless.
By the way, some lame network video cameras are still on the market that can't do modern compression like H.264 and instead just do MPEG2, or worse, Motion-JPEG (M-JPEG). That means they use way more of your network bandwidth than they need to, regardless of the Wi-Fi multicast issue. Make sure you've configured your cameras to stream in H.264, and if they don't support it, return them for a different model that knows how to do modern video compression.
How many devices total are hooked to the router? If you unhook/detach several devices form the router to reduce overall traffic, does the new camera still cause the problems? My thinking is that your using a home-use router as a business-level router, and you've got too many devices for it to handle all the traffic. – Ƭᴇcʜιᴇ007 – 2014-06-12T20:10:26.910
I don't think we ever have over 30 devices connected. At this point though I am willing to try anything, So I tried unhooking everything except this "problem" camera and issues remained. I then tried with everything hooked up except this camera and all works fine. So problem is very camera specific. Thanks for the thoughts – jAce – 2014-06-12T20:37:16.137
If it's the only device causing this, and you've never seen it working properly since you bought it, then it sounds like it could be faulty. Replace the camera with a new/known-good one and try again. – Ƭᴇcʜιᴇ007 – 2014-06-12T20:40:06.090
1@techie007 I doubt his camera is malfunctioning. Sadly, it's trivially easy to take down a Wi-Fi network with a multicast video stream. If you want to do multicast A/V streaming over Wi-Fi, you have to carefully engineer the network. – Spiff – 2014-06-12T21:13:29.170