Real Time Messaging Protocol (RTMP) is a proprietary protocol developed by Adobe Systems for streaming audio, video and data over the Internet, between a Flash player and a server.
The RTMP protocol has three variations:
1. The "plain" protocol which works on top of TCP and uses port number 1935
2. RTMPT which is encapsulated within HTTP requests to traverse firewalls
3. RTMPS which works just like RTMPT, but over a secure HTTPS connection.
While the primary motivation for RTMP was a persistent protocol for Flash, it is also used in some other applications, such as the Adobe LiveCycle Data Services ES.
On 20 January 2009 Adobe announced it will publish the RTMP specification. On 21 May 2009 Adobe filed a DMCA removal request on a Sourceforge-hosted implementation of the protocol.