The four layers of the TCP/IP network protocol stack are listed below:
For each description of tasks performed during the process of downloading a webpage asset, write the letter (A, B, C or D) that matches the layer responsible for that task. Each letter must be used exactly once.
| Description | Letter |
|---|---|
| Establishes a connection via a three-way handshake and reassembles out-of-order segments using sequence numbers. | |
| Determines the MAC address of the next-hop router and encapsulates the packet into a frame for physical transmission. | |
| Parses the HTTP request to retrieve the image file and formats the resource request. | |
| Attaches a header containing the logical destination IP address and uses routing tables to select the optimal path across multiple routers. |
105 exam-style questions on AQA GCSE Computer Science Fundamentals of computer networks. Each one has a worked solution and a mark scheme showing where the marks go.