Tutorial 2

1. How is topology related to line configuration?
Line configuration defines the way two or more devices are connected to a link.Topology is a way two or more links are connected to form a network. Both are used to describe a relationship between communicating devices.

2 Define the three (3) transmission modes.
Simplex defines a one-way communication between two nodes, one, which is always a sender and the other, which is always a receiver. In half-duplex mode, only one station can send at a time. Full-duplex allows both nodes to send and
receive simultaneously.

3. Give the advantages of each type of network topology.
a. Mesh: privacy
b. Star: robustness
c. Tree: isolating and prioritizing communications between different computers
d. Bus: ease of installation
e. Ring: simple fault isolation

4. Give the disadvantages of each type of network topology.
a. Mesh: a large amount of cabling makes it expensive
b. Star: the need for an extra intermediate device
c. Tree: difficult reconfiguration and fault isolation
d. Bus: no privacy
e. Ring: low reliability

5. What are the advantages of a multipoint connection over a point to point connection?
a. Point-to-point: mesh, star, tree, and ring
b. Multipoint: bus

6. What are some of the factors that determine whether a communication system is a LAN, MAN, or WAN?
Size, distances covered by the network, structure, and ownership.

7. What are two (2) types of line configuration?
Point-to-point and multipoint.

8. Name and illustrate the five basic network topologies.
Bus, star, tree, mesh, ring.

9. Distinguish between a peer to peer relationship and a primary secondary relationship.
In a peer-to-peer relationship devices share a link equally; in a primary-secondary relationship the primary controls the access to the medium.

10. Give the formula that finds the number of cable links necessary for a mesh network topology.
n (n – 1) / 2 where n is the number of nodes.

11. For n devices in a network, what is the number of cable links required for a mesh, ring, bus, and star topology?
a. Mesh: n (n – 1) / 2
b. Star: n
c. Ring: n – 1
d. Bus: one backbone and n drop lines

12. Five computers are connected to a common cable in a multipoint configuration. The cable can transfer only 100,000
bits per second. If all computers have data to send, what is the average data rate for each computer?

13. For each type of network topology, discuss the implication of a single cable fault.
a. Mesh: communication will stop only between the devices connected by the
faulty link
b. Star: same as a mesh
c. Tree: depends on the kind of link (if a link is impaired between two hubs, communication
will be disrupted for the whole subnetwork)
d. Bus: all transmission will stop
e. Ring: a fault in one link can impair the whole network


14. What is an internet. What is the Internet?
An internet work is an interconnection of networks. The Internet is the name of a
specific worldwide network.