AQA GCSE Computer Science - 3.5 Fundamentals of Computer Networks-practice questions with complete solutions

Protocol Special set of rules that the computers use when they communicate e.g. Http, TCP, IP HTTP Protocol used used to transmit unencrypted webpages between a server and a client. (The server is a Web Server and the Client is the device receiving the web page and displaying it using a Web Browser). HTTPS Protocol used used to securely transmit encrypted webpages between a server and a client using SSL (Secure Sockets Layer) (The server is a Web Server and the Client is the device receiving the web page and displaying it using a Web Browser). TCP Protocol used to maintain a link between devices when transmitting data, to break the data down into packets and to check all packets have reached their destination. Resends lost packets using a system of ACKs. Stands for Transmission Control Protocol. Part of the Transport Layer IP Protocol that adds sender and recipient addresses to packets and decides the best route to send each one. Part of the Network / Internet Layer. FTP Used to transfer files between and client and a server on a network. File Transfer Protocol. SMTP Used for sending e-mail messages from the client to the server and between servers. Simple Mail Transfer Protocol. POP Used by the client to retrieve email messages from the email server. Messages are deleted from the server once transferred to the client. Post Office Protocol. Largely not used anymore. IMAP Used by the client to retrieve email messages from the email server. Mail is kept on the server once downloaded. Internet Message Access Protocol. Application layer Top layer. Used to encode the data so that it can be understood by the receiving computer. Encoding uses the correct protocol for the application - e.g. HTTP / FTP / SMTP. Transport layer Second layer in the TCP/IP stack. Sets-up a connection between the two hosts, agrees the protocol and packet size. Splits data into packets, adds the packet number and total number of packets (so they can reassembled correctly). Network / Internet Layer Third layer in the TCP/IP stack. This layer adds destination and sender IP addresses and handles packet routing. Data Link layer Fourth layer in the TCP/IP stack. This layer adds MAC address of the sender and the recipient so that the data can be transmitted physically between networked devices. Wi-Fi A trademarked name used by manufacturers that shows a piece of equipment can be connected to a Wireless Network.