By Kevin Lee

You may have heard the words "Video on Demand" and "Streaming Media" while surfing the Web. These terms refer to technologies used to transfer audio and video content from a remote location to your computer. RTMP and RTSP are two of those technologies. RTMP and RTSP communication protocols share more similarities than differences and help make real-time interactive multimedia distribution possible.

Communication Protocols

The word HTTP, seen in URLs, stands for Hypertext Transfer Protocol . A protocol is a set of rules that define how systems exchange information and communicate. Websites distribute hypertext content, audio and video using this HTTP. All browsers support this protocol, and it requires no special knowledge to use it. Simply place an HTML document on your Web server, and the rest of the Internet sees it. Video transmitted using HTTP loads progressively into a browser, and you cannot view it all until the video downloads. To perform real-time streaming, you must use protocols such as RTMP and RTMS.


Adobe, which distributes the Flash player, created RTMP to help Web servers stream low-latency, on-demand content across the Web efficiently. Low latency is important when you wish to view smooth video in your browser. RTMP servers, such as the Flash Media Server, also support live video transmissions and can stream audio and other types of data as well. If someone loses an Internet connection while viewing our RTMP content, the system can reconnect and resume streaming. Internet users enjoy videos that start faster and play smoothly when viewing streaming content using RTMP.


Developers originally designed on-demand technology to allow people to control media using familiar Play, Pause and Stop controls. RTSP, which also delivers real-time streaming, allows you to control playback using these types of controls. You can even advance to the end of a video without downloading the entire file. RealNetworks, creator of the Real Player, used RTSP audio and video streaming in the '90s. Developers also use RTSP to create instant messengers, video conferencing software and other types of applications that require real-time interaction.


You need a special server such as the Flash Media Server to distribute video content using RTMP. You can use the server to send data to Adobe Air and other Adobe applications that support streaming media. Even though Adobe created RTMP, developers can use it in their own applications because the company released the technology to the public. You also need a special server to deliver RTSP content. One disadvantage of using RTMP and RTSP is the need to use special servers. Many websites deliver video successfully using regular HTTP even though it only provides progressive pseudo-streaming. However, you may benefit from using RTMP or RTSP when you need to stream real-time video on demand or broadcast live events.