Windows Media streaming
About Windows Media
[[wikipedia:Windows Media|Windows Media] is a format for lossy audio and video transmission by Microsoft. The audio format is known as WMA (file extension .wma).
In streaming WMA is transferred over a protocol called MMS (Microsoft Media Server).
MMS disambiguation
The name MMS (Microsoft Media Server) is a bit confusing as it is often used to describe different protocols.
There are three protocols often called as MMS based on a similar protocol: MMS over HTTP, MMS over TCP and MMS over UDP.
The Streaming Client supports MMS over TCP and MMS over HTTP. For these protocols the following URL prefixes are commonly used: http://, mms:// and mmst://
For even more confusion the http:// prefix is widely used for Shoutcast servers.
The following table explains the URL prefixes used by the Streaming Client:
| Protocol | Prefix used by the Streaming Client | Commonly used prefix |
| Shoutcast | http:// | http:// |
| MMS over HTTP | mms:// | http:// |
| MMS over TCP | mmst:// | mms:// or mmst:// |
MMS in the Streaming Client
Until February 2008 the MMS protocol was proprietary and the only way to implement non-Microsoft player was to reverse-engineer the protocol. In February 2008 Microsoft deprecated the MMS in favor of RTSP and released the MMS specifications to the public.
Limitations
The Streaming Client implementation still uses the reverse-engineered protocol and therefore is not 100% compatible with all servers. The Streaming Client supports audio-only streams (some streams are mixed video and audio) and only streams with one bitrate (some servers send multiple bitrates at the same time).
Shall I use MMS or MMST?
If you get a URL use the above table to select the proper protocol in the Streaming Client.
Most Windows based internet radio servers stream in MMS over HTTP. Therefore try this option first.
Most servers also provide both MMS over HTTP and MMS over TCP, but it is not automatically in all cases (must be enabled on the server). If you own the server and can configure it, allow both options.
If MMS over HTTP does not work or you experience problems try MMS over TCP and vice versa. However, MMS over HTTP should be more reliable.
