It is possible to write a Silverlight client that understands Adobe's RTMP protocol if you really need it, but for non-live streaming to a Silverlight player i

It is possible to write a Silverlight client that understands Adobe's RTMP protocol if you really need it, but for non-live streaming to a Silverlight player i recommend IIS with smooth streaming on the origin server(s). The media chunks are delivered through HTTP so any CDN will do.