The structure of a RTP packet is shown below.
The real-time media that is being transferred forms the 'RTP Payload'. RTP header contains information related to the payload e.g. the source, size, encoding type etc. We will go through the header structure in the next page.
However the RTP packet can't be transferred as it is over the network. For transferring we use a transfer protocol called User Datagram Protocol (UDP). We won't discuss UDP header.
To transfer the UDP packet over the IP network, we need to encapsulate it with a IP packet. We won't discuss IP header either. To transfer the IP packet over the physical network even the IP packet is sent within other packets. Those are not shown here.