Here is my situation and conclusions:
1 - wireless is disabled, everything is CAT6 and everything is Gb nics, switches & router, fw 1.21
2 - when I run the streaming machine through the DLink DGS-2205 GB switch, everything is fine with 4k jumbo frames.
3 - when I run the streaming machine through the DIR-655 router, the router chokes on the stream and drops it, jumbo or not - tried 2,3 & 4k jumbo. Tried port forward, QOS priority, etc and so forth.
Therefore, the router can not handle the stream but the switch can. Any theories?