I did a search for mms:// protocol and came up with the following:
MMS or ' Microsoft Media Server ' protocol is Microsoft's proprietary network streaming protocol. Microsoft has never released a specification to describe how MMS actually works, yet it is extensively used by their Microsoft media player software. MMS protocol can be used on top of TCP and UDP transport protocols over any network medium. Its primary use is to stream live or prerecorded audio and video content to your computer without any need to download a file before playing.
http:// protocol is the default protocol for webpages (http servers) and are typically accessed via a web browser. ftp:// protocol is the default protocol for file transfer (ftp servers) and are typically accessed via an ftp client. Similarily mms:// protocol is Microsoft's protocol for media and is accessed via Microsoft Media Player.
Bandwidth isn't an issue here. Regardless of whether you download a 10mb file via http:// or via ftp:// it is still 10mb regardless and will take the same amount of time to download.
Although I have no experience with mms:// my guess is that it is a form of streaming media. When accessing media over http://, it isn't streaming by default but it can be configured on the server's end to do so. This means that you can listen/watch the first part of the media file while it finishes downloading the end part you haven't gotten to yet. This way you don't have to wait for the entire thing to download before you can start playing it. Of course, it still takes just as long to get to your computer when all is said and done. It's just that when it's streaming, you can start playing it before it finishes.
Dani the Computer Science Gal
