Computer Communication Network
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1-What is a computer communication network? Network is a set of devices (often referred as nodes) connected by media links. 2-What are the advantages of using computer network? 1. 2. 3. 4. 5. 6.
Resource Sharing. High reliability and performance. Cost saving. Access to remote information. Person-to-person communication. Interactive entertainment.
3-Identify the five components of a data communication system 1. 2. 3. 4. 5.
Message. Sender. Receiver. Medium. Protocol.
4-What are the three criteria necessary for an effective and efficient network? 1. Performance. 2. Reliability. 3. Security. 5-Name the factors that affect the performance of a network? 1. Number of users. 2. Type of transmission medium. 3. Hardware / Software of the nodes. 6-Name the factors that affect the reliability of a network? 1. Frequency of failure. 2. Recovery time after a failure. 3. Protection against catastrophic events such as fire, earthquake, and theft. 7-Name the factors that affect the security of a network? 1- Unauthorized access. 2- Viruses.
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Computer Communication Network
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8-What are the services of computer networks? 1. File transfer 2. Email 3. Error detection / recovery 4. Web / HTTP services 5. Authentication 9-Define the following terms:
6. Addressing 7. Routing 8. Flow control 9. Buffering 10. Security services Internet – intranet - extranet
"Internet":
- The global internet which utilizes TCP/IP suite of protocols. - There is only one "Internet".
"intranet":
- A type of internet. - Often referred to as an organization's private internal network which utilizes TCP/IP.
"extranet":
- Another type of internet. - Often referred to as a protected extension of an organization's private internal network which expands and interconnects with other public and/or private networks.
10-What are the network categories? 1. LAN (Local Area Network). 2. MAN (Metropolitan Area Network). 3. WAN (Wide Area Network). 11-What are some of the factors that determine whether a communication system is LAN, MAN, or WAN? 1. 2. 3. 4.
The size. Its ownership. Its physical architecture. The distance it covers.
12-State the advantage of Integrated Services Digital Network (ISDN). 1. Designed to replace public telecom system. 2. Wide variety of services. 3. Entirely digital domain. 13-State the technologies that are used in WAN. 1. 2. 3. 4.
Circuit switching. Packet switching. Frame relay. Asynchronous Transfer Mode (ATM).
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Computer Communication Network
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14-Identify the four standard topologies for LAN. 1. 2. 3. 4.
Tree. Bus. Ring. Star.
15-Write a short account on the following, use drawing whenever possible: i- Circuit Switching ii- Packet Switching iii- Frame Relay iv- Asynchronous Transfer Mode (ATM) Circuit switching:
Dedicated communication path established for the duration of the conversation (Ex. Telephone Network).
Packet switching:
- Data sent out of sequence. - Small chunks (packets) of data at a time. - Packets passed from node to node between source and destination. Ex. Terminal <-> Computer
&
Computer <-> Computer
Frame Relay:
- Fast packet-switched data transport technology - Assume error-free lines - All validation and error correction to end device, which results in having more processing capacity to deliver additional network throughput
ATM
- Evolution of frame relay. - Little overhead for error control. - Fixed packet (Called cell) length. - Anything from 10 Mbps to Gbps. - Constant data rate using packet switching technique.
Note: Throughput is: The amount of data transferred from one place to another or processed in a specified amount of time. Data transfer rates for disk drives and networks are measured in terms of throughput. Typically, throughputs are measured in Kbps, Mbps and Gbps.
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