What is RTP (Real-time Transport Protocol)? The RTP is a simple way of sending and receiving encoded video, audio, and data in connectionless network sessions. It provides headers that give VoIP systems an easy way of selecting between multiple sessions on the same host machine. Throughout this paper, I will illustrate what the real-time transport protocol is, why it is used in transporting data, and some of the RFCs that are relevant to the RTP.
The RTP “provides end-to-end network transport functions suitable for applications transmitting real-time data, such as audio, video or simulation data, over multicast or unicast network services. RTP does not address resource reservation and does not guarantee quality-of-service for real-time services” (RFC 3550, 2003). In other words, it provides various forms of data a means to get to and from its source and destination. However, it does ...view middle of the document...
Without technologies like RTP, we wouldn’t be able have these kinds of transmissions. However, RTP isn’t able to all of this alone; there has to be some form of control in order for the technology to work. This is where RTCP (Real-Time Transport Control Protocol) comes into play. This protocol controls RTP’s media sessions and all of the collection of all of the data that is relevant to those sessions. Without RTCP, data would be getting lost in the void somewhere. Together though, RTP and RTCP provide several different functions. They packetize and transport digitized, encoded voice and/or video signals (including unique identification of each RTP stream), they multicast sessions for conferencing applications, and they handle basic performance feedback about the utilization of RTP media sessions. This means that systems administrators barely have to worry about these protocols inner workings because they practically run themselves upon implementation. Next, I will be discussing an RFC which puts RTP into a professional perspective.
RFC 1889 defines RTP as providing end-to-end delivery services for data with real-time characteristics, such as interactive audio and video. The services it’s referring to, includes payload type identification, sequence numbering, time stamping, and delivery monitoring. It goes on to describe the applications which are typically ran using RTP are on top of UDP because it makes use of its multiplexing and checksum services. Both protocols contribute parts of the transport protocol functionality.
In conclusion, the RTP is a protocol used to transport real-time video, audio, and data via network sessions (connected and connectionless). RTCP provides the control portion of RTP media transmissions; without it, RTP would not work properly. RFC 1889 and 3550 go into a lot of depth on what RTP is, and how it came about. RFC 1889 was obsoleted by 3550 in 2003.
Casner S.L., Frederick, R., Jacobson, V. (2003). RFC 3550. RTP A Transport Protocol for Real-Time Applications. The Internet Society. Retrieved from:
Some Frequently Asked Questions about RTP. (2004). Retrieved from: