1. S HEET I C HAPTER 1 + C HAPTER 2 Imane M. Amin Fahmy Ismail

2. Q UESTION 1: M ARK AS T RUE (T) OR AS F ALSE (F): Frame relay networks are designed to operate efficiently at high error rates. ( F ) The television broadcast transmission is considered as an example of simplex transmission. ( T ) The network access layer contains the logic needed to support the various user applications. ( F ) Flow control is a function of the network layer. ( F ) The maximum bandwidth of twisted pair is higher than coaxial cable. ( F )

3. Q UESTION 2: C HOOSE THE CORRECT WORD ( S ) TO COMPLETE THE FOLLOWING SENTENCES : The scope of LAN is small interconnecting a single building or a cluster of buildings. ATM uses fixed-length packets, called cells. Frame relay was developed to take advantage of: High data rates and Low error rate The source generates data to be transmitted. Internet Layer provides procedures used to allow data to traverse multiple interconnected networks, to provide communications between devices attached to different networks.

4. Q UESTION 3: G IVE ONE FUNCTION FOR EACH OF THE FOLLOWING :  The Transport Layer: This layer is responsible of providing a reliable delivery of data in the same order as sent. The commonly used transport protocol is the Transport Control Protocol (TCP)  The Network Access Layer: This layer is concerned with the exchange of data between an end system (server, workstation, etc.) and the network to which it is attached.

5. Q UESTION 3: G IVE ONE FUNCTION FOR EACH OF THE FOLLOWING :  The TCP/IP protocol: A standard protocol for packet switched network used by the global Internet protocol and comprises a large collection of standardized protocols  The ISP: The Internet Service Provider company that provides other companies or individuals access the internet through its telecommunications line and equipments.

6. Q UESTION 3: G IVE ONE FUNCTION FOR EACH OF THE FOLLOWING :  The Asynchronous Transfer Mode (ATM): This evolutionary technology came after frame relay but using the fixed packet length called cell. It offers little overhead for error control and higher data rates reaching Gbps ranges

7. Q UESTION 4: D IFFERENTIATE BETWEEN THE FOLLOWING : Circuit SwitchingPacket Switching A dedicated communication path established between two stations No dedicated path. Data are sent in a sequence of small chunks called “Packets” (64Kbps) Each node relays or route data over the path without delay. The data rate is constant over the link. Each node on the path: receive, store and re-transmit packets (use error control at each node) Ex: The telephone networkTerminal-to-computer and vice versa Frame RelayATM (Asynchronous Transfer mode) Data are sent in a sequence of variable size packets “frames” for higher data rates (up to 2Mbps) and lower error rate Data are sent in a sequence of fixed size packets “cells” (Cell relay). For higher data rates (Gbps) and nearly constant data rate on multiple chan. Error control is at end systems only. Error control at end systems only. Evolution from packet switching.Circuit switching + Packet switching

8. Q UESTION 4: D IFFERENTIATE BETWEEN THE FOLLOWING : LANWAN Local Area NetworksWide Area Networks Covers a small area (office, floor, building or group of buildings) Covers a large geographical area (countries or continents) Limited number of usersEnormous number of users TCP segmentIP datagram A TCP (Transport Control protocol) segment created by appending a TCP header of control information to each piece of data The IP (Internet Protocol) datagram created by appending an IP header of control information to each TCP segment Destination port, Seq. num, checksum The destination address

9. Q UESTION 4: D IFFERENTIATE BETWEEN THE FOLLOWING : SMTPFTP The Simple Mail Transfer Protocol The File Transfer Protocol Provides a basic local electronic mail transport Used to send files from one system to another under user command

10. T HANK YOU Any Questions?