With the popularity and rapid evolution of mobile devices watching videos and video-phone applications are becoming standard and even necessary. This provides an opportunity for live media streaming application development. For these networks traffic monitoring and analyzing is essential.
The aim of this paper is to plan and develop an application which is capable of streaming media between mobile devices, can monitor network traffic and can gather data about it. The application can send the video recorded through the device’s camera over an RTP stream with minimal delay.
How does it actually work? When the user start the application, (s)he can choose between joining an existing video stream, or creating one. If the user chooses to join an existing one, first the two devices go through an initialization, where the one who wants to connect sends a query and the other device responds with an acknowledgement and the parameters needed to play the data from the stream. When the client receives the acknowledgement it starts to play the stream. On the other hand, when the create stream option is chosen, the application displays the camera preview on the screen and starts listening for client requests. When the request is received the transmission is started. The audio and video components are sent separately on different streams and the video part is sent frame by frame.
The data about the stream and network traffic is collected on the device which created the stream. The following values are saved for each packet: sequence number, timestamp, client side received time, delay and jitter. The delay is measured by active monitoring where the client sends a reply when it receives a packet. That packet contains the information which is saved. The delay is computed from the sending time of the packet and from the received time of the reply.