A network is a set of devices connected by physical media links. A network is recursively is a connection of two or more nodes by a physical link or two or more networks connected by one or more nodes.
At the lowest level, a network can consist of two or more computers directly connected by some physical medium such as coaxial cable or optical fiber. Such a physical medium is called as Link.
A network can consist of two or more computers directly connected by some physical medium such as coaxial cable or optical fiber. Such a physical medium is called as Links and the computer it connects is called as Nodes.
4. Explain a gateway or Router?
A node that is connected to two or more networks is commonly called as router or Gateway. It generally forwards message from one network to another.
If the physical links are limited to a pair of nodes it is said to be point-point link.
If the physical links are shared by more than two nodes, it is said to be Multiple Access.
7. Describe the advantages of distributed processing?
☛ Security/Encapsulation
☛ Distributed database
☛ Faster Problem solving
☛ Security through redundancy
☛ Collaborative Processing
8. Tell me the criteria necessary for an effective and efficient network?
☛ Performance:
It can be measured in many ways, including transmit time and response time.
☛ Reliability:
It is measured by frequency of failure, the time it takes a link to recover from a failure, and the network's robustness.
☛ Security:
Security issues includes protecting data from unauthorized access and viruses.
9. What are the factors that affect the performance of the network?
☛ Number of Users
☛ Type of transmission medium
☛ Hardware
☛ Software
10. What factors that affect the reliability of the network?
☛ Frequency of failure
☛ Recovery time of a network after a failure
11. What factors which affect the security of the network?
☛ Unauthorized Access
☛ Viruses
12. What do you know when a switch is said to be congested?
It is possible that a switch receives packets faster than the shared link can accommodate and stores in its memory, for an extended period of time, then the switch will eventually run out of buffer space, and some packets will have to be dropped and in this state is said to congested state.
13. Explain a peer-peer process?
The processes on each machine that communicate at a given layer are called peer-peer process.
14. Can you please explain the difference between Bandwidth and Latency?
Network performance is measured in Bandwidth (throughput) and Latency (Delay). Bandwidth of a network is given by the number of bits that can be transmitted over the network in a certain period of time. Latency corresponds to how long it takes a message to travel from one end off a network to the other. It is strictly measured in terms of time.
The process of determining systematically hoe to forward messages toward the destination nodes based on its address is called routing.
16. Tell me the key design issues of a computer Network?
☛ Connectivity
☛ Cost-effective Resource Sharing
☛ Support for common Services
☛ Performance
17. List the key elements of protocols?
The key elements of protocols are:
☛ Syntax:
It refers to the structure or format of the data, that is the order in which they are presented.
☛ Semantics:
It refers to the meaning of each section of bits.
☛ Timing:
Timing refers to two characteristics: When data should be sent and how fast they can be sent.
Defining a useful channel involves both understanding the applications requirements and recognizing the limitations of the underlying technology. The gap between what applications expects and what the underlying technology can provide is called semantic gap.
The duration of time it takes to send a message from one end of a network to the other and back, is called RTT.
20. What is unicasting in network engineering?
If the message is sent from a source to a single destination node, it is called Uni-casting.
21. What is multiccasting in network engineering?
If the message is sent to some subset of other nodes, it is called Multicasting.
22. What is broadcasting in network engineering?
If the message is sent to all the m nodes in the network it is called Broadcasting.
Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link.
24. List the categories of multiplexing?
☛ Frequency Division Multiplexing (FDM)
☛ Time Division Multiplexing (TDM)
1: Synchronous TDM
2: ASynchronous TDM Or Statistical TDM.
☛ Wave Division Multiplexing (WDM)
FDM is an analog technique that can be applied when the bandwidth of a link is greater than the combined bandwidths of the signals to be transmitted.
