Question

List three applications that use UDP and three applications that use TCP and explain why those applications use the selected Transport layer protocol.

Answer 1

As you know in when we send a message to the receiver it passed through multiple layer. Among that at transport layer we use either TCP or UDP as a internet protocol. TCP is Transmission control Protocol which is a connection oriented protocols it uses 3-way handshake method to connection establishment.. Means it will need a proper connection before sending message through. On the other hand UDP is a User Datagram Protocol which is a connection less Protocol. In this UDP, you can send any small message but it will not guarentee whether the message will deliver correctly or not. But TCP takes care of that.

TCP Get used in the below applications

1.World Wide Web(HTTP) : HTTP uses TCP as a transport layer protocol because whenever we search anything on the browser then from server the data get fetched into the browser because of TCP . The TCP takes care of delivering the data to the browser without any loss or duplicate. It ensures that. Also if any data loss happened it will resend the data . so that consistency will be there. Thats why we TCP get used in HTTP .

2.E-mail (SMTP) SMTP is simple mail transfer protocol which is a communication protocol in case of mail.when u send any mail this SMTP send that mail to the receiver . This is also using TCP because it ensures that if you sent any packet or mail to user the same should be get deliver to the receiver.The TCP uses Checksum to find out if any error is there in the message bit or if any message bit get corrupted . then in that case also the checksum help to find out the error and resend the message to fix the issue.

3.File Transfer Protocol (FTP) FTP is the file transfter protocol which transfer a file between two nodes. whenever a sender and receiver get connected through FTP . then TCP connection is got establish between those two nodes. TCP takes care of all packets got send to receiver correctly . Also to the exact destination with the port address.

We use TCP to handle all kind of issue during the transmission of any message . because other protocols like FTP, SMTP or HTTP they dont have their own methods or any ways to handle the loss of message or corrupt message.

UDP Get used As transport layer protocol In below applications:

1. Trivial File Transfer Protocol (TFTP) : As name suggesting Trivial FTP . A TFTP protocol uses UDP because TFTP have all the methods to handle the errors in data, loss of packet issue or acknowledge loss issue. Its having those power to handle . As UDP is not very reliable protocol. but it is very fast as compared to TCP . because TCP has overhead. which takes time at transport layer. But this udp will work fastly .So we use UDP for TFTP.

2. Domain Name System (DNS) DNS uses UDP on port 53 . UDP is preffered in that case when the message need to deliver fastly. UDP has less overhead. so it devlier fastly. but not reliable . doesnt have any power to find the corrupt message or to find the lossed packet. DNS requests are very less size or very small. thats why it fits into the segment well. As its reliability is less so that can be handled on the application layer

3. Network Time Protocol(NTP) : it is the oldest network protocol which in used currently also. this uses UDP because it is very fast in response and connection setup is also takes very less time.