rtspdump is a program which downloads multimedia stream (such as
live broadcasts) from a Microsoft WMServer.

Are you stumped by error messages from all open source video playing
tools when you try to access a MMS or RTSP form URL?

You are probably trying to access a Windows Media Server that
nowadays only supports RTSP traffic; the old MMS protocol is
discarded.

The catch is, being Microsoft, they have used a RTSP-like
implementation, which is modified with Microsoft's own quirks. So
it is not standard form anymore.