RTSP is used for controlling streaming media over the web. It allows for audio and video-on-demand streaming to large groups. RTSP uses directives like OPTIONS, DESCRIBE, SETUP, PLAY, PAUSE, and TEARDOWN to control the stream. SDP is used to describe the metadata of the stream, including information like the session name, connection details, media formats, and attributes. Common RTSP operations include requesting information with OPTIONS, retrieving the SDP description with DESCRIBE, setting up transports with SETUP, starting and pausing playback with PLAY and PAUSE, and terminating the session with TEARDOWN.

1. RTSP SDP Wireshark Analysis

4. Client Server HTTP GET Stream URI SETUP PLAY RTP Media Stream PAUSE TEARDOWN DESCRIBE OPTIONS RTP Media Stream SDP Information Web Browser Media Player Media Server Web Server

7. Initiation Handling Termination

10. DESCRIBE is used to retrieve the description of the media URL and the session. The description response MUST contain all media and streaming data needed in order to initialize the session. Fields: Accept - Used to inform the server which description methods the client supports. Session Description Protocol (SDP) is highly used. Notice that CSeq field is increased by one. Description readers

11. Description readers SDP The response will always return the details of the media. SDP details will be next… The media URL the response is referring to The description method used The length of the SDP message

12. GET_PARAMETER is used to retrieve information about the stream. The request can be initiated from the Client or from the Server. The request/response message body is left to server/client implementation. The parameters can be: packets received, jitter, bps or any other relevant information about the stream.

13. SETUP is used to specify the transport details used to stream the media. The request/response message body is left to server/client implementation. The parameters can be: packets received, jitter, bps or any other relevant information about the stream. Transport protocol Unicast/Multicast RTP/RTSP client media port Track ID

14. SETUP response will contain the session ID. For each track ( audio/video ) a different SETUP request will be made After the response is received, a PLAY request can be made to start receiving the media stream. Transport protocol Unicast/Multicast server option Unicast destination ip Last gateway source ip The client port to receive media data The server port to receive media data

15. PLAY request tells the server to start send data through the streaming details defined in the SETUP process. PLAY request maybe queued so that a PLAY request arriving while a previous PLAY request is still active is delayed until the first has been completed. Normal Play TIme

16. Stream URL PAUSE request tells the server to pause the streaming. When the user will want to start the stream again he’ll send a PLAY request to the same URL. The request may contain time information to handle when the pause will take effect.

17. TEARDOWN stops the stream delivery for the URL specified. Informs the server that the client is disconnecting from it. The response will include only the response code. Description readers