Using the MMS protocol

The Microsoft Media Server (MMS) protocol is a proprietary streaming media protocol developed by Microsoft for earlier versions of Windows Media Services. You can use the MMS protocol when delivering content as a unicast stream. It supports player control actions such as fast-forwarding, rewinding, pausing, starting, and stopping an indexed digital media file. If you are supporting clients that are using earlier versions of Windows Media Player, you will need to use either the MMS or the HTTP protocol to service their stream requests.

MMS protocol overview

If the connection URL specified by the Player uses MMS (for example, mms://server_name/publishing_point_name/file_name), then the Player can use protocol rollover to negotiate the best protocol to use. MMSU and MMST are specialized versions of the MMS protocol. MMSU is a User Datagram Protocol (UDP)-based protocol, which is the preferred protocol for streaming. MMST is the Transmission Control Protocol (TCP)-based protocol used on a network that does not support UDP.

If you want to force the server to use a specific protocol, you can identify the protocol to be used in the announcement file. The user can also specify the protocol in the content address (for example, mmsu://server_name/publishing_point_name/file_name). To facilitate protocol rollover, it is recommended that the URL use the generalized MMS protocol. That way, the Player can use either the MMSU or MMST protocols to connect to the stream. If the Player cannot connect to the stream successfully by using either of these protocols, it attempts to connect to the stream by using Hypertext Transfer Protocol (HTTP). For more information about protocol rollover, see How protocol rollover works.

Windows Media Services implements the MMS protocol through the WMS MMS Server Control Protocol plug-in. In a default installation of Windows Media Services, this plug-in is enabled and bound to TCP port 1755 and UDP port 1755.

Note Image Notes

When setting up distribution servers for the Fast Streaming feature, use either the RTSPT or HTTP protocols to connect to the origin server. For more information about Fast Streaming, see Understanding Fast Streaming. For more information about distribution servers, see Using distribution servers.
Some ISA clients may have trouble connecting to port 1755. To correct this problem, create a file called Wspcfg.ini and save it to the folder named %systemroot%\Windows\System32\Windows Media\Server. The file should contain the following text:
```
[WMServer]
LocalBindTcpPorts=1755
LocalBindUdpPorts=1755
```

Using the MMS protocol

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