Outline the functions of the Transport and Internet layers of the TCP/IP protocol suite.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2022). The mark or mark type is shown in brackets.

1. [5] One mark for each point (Max 3)
2. MP1 The Transport Layer breaks data into manageable packets / performs segmentation
3. MP2 It sequences the packets // adds data to the packet header // adds a packet header
4. MP3 It sends the packets to the Internet / Network Layer // It receives data from the Application Layer
5. MP4 It controls the flow of packets
6. MP5 It handles packet loss/corruption // Acknowledges receipt of complete error free packets
7. One mark for each point (Max 3)
8. MP6 The Internet Layer identifies the intended network and host
9. MP7 It transmits packets to the (Data) Link / Physical Layer
10. MP8 It routes the packets independently through the optimum route
11. MP9 It addresses packets with their source and destination IP addresses
12. MP10 It then uses an IP address and port number to form a socket.