Streaming video over wifi to windows media center...problems

My current set up is as follows:
Dlink dual band wireless a/b/g/n router
Netgear NAS server connected via ethernet to Dlink (Gig Ethernet Connection)
streaming to
Sony Media Center PC (running windows 7). Linksys Wireless N (2.4Ghz) pcmia slot

Type of files: .avi video files

Problem: the connection is excellent over the wireless n adapter. On the Sony PC I configure media center to view the .avi video files on the NAS server thru the mapping feature. When I select the video file to play it goes thru phases of clipping and buffering throughout the movie.

Could anyone help in providing some insight on if this is a simple problem to resolve or a known issue? also I would like to know what port the video uses and protocol to stream the video from the NAS server/WIFI router to the Sony Media Center PC....If I know the port and protocol, I may be able to set up a direct route from the router to the pc or setup priority cueing.....that information would be very helpful....thanks....

Email Address: dcpapa@gmail.com