Why can't I connect to the MMS server using the MMS protocol?

When developing a network radio application, it is found that the original app is always unable to connect successfully when accessing the MMS server. Sometimes it is connected to the server, but when sending commands, unable to obtain the response; similarly, the PC-Side Software SDP downloader cannot be connected. These servers use WMP for connection. But through wireshare capture found that the RTSP protocol is used, and then the internet search found that there is a protocol flip this thing: From http://technet.microsoft.com/zh-cn/library/cc771761 (ws.10). aspx

Windows Media Services can use the correct protocol to deliver content to Windows Media Player. This function is called protocol flip. If you support different Player versions (players connected through firewalls or players connected through different types of networks), Protocol flip is very useful. If all the server control protocol plug-ins (including wms http Server Control plug-ins) on the server are enabled, the Protocol rolling execution is the best.

The player uses protocol flip to establish the optimal connection with the server. When the player tries to connect to the server, it sends information about its type and the protocols it supports. Windows Media Server compares the information with the enabled protocol and then uses the protocol that best suits the situation. Generally, you can establish a connection between the player and the server for the first time without performing any other operations. If the connection request fails, the player tries to connect to the server using other protocols it supports. During each attempt to perform a protocol flip, the player will experience a very short delay that is usually not noticed.

The logic used for protocol flip varies with the player version.

To support the maximum number of Stream Player versions, use the mms url tag (MMS: //) in the connection URL to the stream content ://). The mms url mark allows all connected players to use protocol flip and use the best stream protocol to transmit content. If you use announcements to enable the player to access your content, the mms url is automatically used to identify the content. Therefore, you can perform protocol flip when necessary. Note that you can disable the protocol in the player attribute settings. If the player only supports a single protocol, it cannot be flipped. In addition, be sure to select the data transmission protocol (RTSP or
HTTP) Open the firewall port.

In some cases, a player that does not support MMS streams (such as Windows Media Player 11) may fail to transmit your content for one of the following reasons:

• The player successfully selects the alternate stream protocol during protocol flip, but the Windows Media Server that hosts your content does not enable the control protocol plug-in used for the selected stream protocol (RTSP or HTTP. Note that the wms http server control protocol plug-in for managing HTTP streams is disabled by default in Windows Media Services.

• The player successfully selects the backup stream protocol during protocol flip, but Windows Media Server cannot pass the content through your firewall.
• The player cannot use protocol flip to select the standby stream protocol because it is not in the player"Network"On the tab, configure the stream protocol and proxy settings correctly.

Remarks
The MMS stream protocol has been deprecated since the Windows Media Services 9 series for Windows Server 2003. Therefore, the support for MMS streams is limited to Windows Media Player for Windows XP or earlier versions. The MMS stream protocol is no longer supported since Windows Media Services for Windows Server 2008.

That is to say, when the MMS protocol is used for connection, if the server chooses to use RTSP for transmission, the player also needs to reverse the protocol and use the backup stream protocol.