Question

- If you were to design a new application layer protocol to stream videos over the Internet, what transport layer protocol would you use, and why? What are the features of that protocol that make it suitable for your purpose?

- From application layer to physical layer and back again, explain the process that a single packet message goes through to get encapsulated? What information is added at each layer. Clarify your assumptions. Is this an IPv4 or v6 network, or some other protocol entirely? On the receiving end, what, if anything, does each layer do or look for as it receives a packet?

Answer 1

Ans: - TCP protocol is used to transfer data from source to destination. Data is divided into the smaller pieces called packets. If there is a need to design an application layer protocol for streaming videos then HTTP based protocols are used to do the same. These protocols are present in Application layer of the Transmission control protocol.

As in this modern age online video streaming platforms have become the most useful source for accessing any type of information. Because video contents could be easier to understand as compare to text.

Real Time Streaming Protocol (RTSP) is the HTTP based protocol in the Application layer of TCP protocol which can be used to transmit the live data streaming from source to destination. It also used the user datagram protocol and transmission control protocol for streaming purposes.

Features of RTSP :-

RTSP is a transport protocol which is used to transfer data consist of This protocol has MP3, MP4, AAC, AAC-LC, Opus and Vorbis Audio codecs and H.265 H.264, VP9, VP8 video codecs.

This can use both UDP and TCP for data transmission.

It has high fault tolerance which decrease the rate of failure in transmission of the data.

It is highly scalable which provide the feature of publish the large subscribers userbase.

The best advantage of this protocol is that it has Low-latency. Latency is the delay before the transmission of data or information. There is no requirement of buffering. So that this protocol can be of best use to stream online videos.

Data Encapsulation process: -

How the data travels from the application to physical layer or over the whole TCP suite.

Application layer of TCP displays the actual data which the end user sees. Physical layer defines the hardware structure of network.

Firstly, the data is converted into small packets and these packets are transferred over the different layers using the various addressing techniques. To check whether the data sent by the sender has reached its destination different error and flow control methods are used. Data should reach the destination in the same form as it was sent by the sender.

At application layer the user initiates the communication process by sending the data. Then at Transport layer data gets encapsulate in the following steps: - TCP Segmentation, the transport layer receives the data sent by application layers as an input. The received data is divided into segments, each segment has header assigned to it. Then the TCP connection is established by using the ACK (Acknowledgement) and NACK (Negative Acknowledgement). When data is successfully received by the receiver it sends ACK message which is positive acknowledgement otherwise it sends negative acknowledgement. UDP protocol coverts the arrived data into UDP packets and then forward it to internet layer. At IP layer the data is converted into frames by the IP datagram. Then the data received by the physical as input from IP layer and establish it over the network media.

This network uses IPv6 protocol fro addressing the data information.