TYPES OF NETWORKS

Question 1

GEOGRAPHICALLY

What is a LAN? And what are it’s characteristics?

Answer 1

A LAN is a network infrastructure that spans a small geographical area. LANs have specific characteristics:

1. LANs interconnect end devices in a limited area such as a home or campus.
2. A LAN is usually administered by a single organization or individual. Administrative control is enforced at the network level and governs the security and access control policies.
3. LANs provide high-speed bandwidth to internal end devices and intermediary devices

Question 2

GEOGRAPHICALLY

What is a WAN? And what are it’s characteristics?

Answer 2

A WAN is a network infrastructure that spans a wide geographical area. WANs are typically managed by service providers (SPs) or Internet Service Providers (ISPs).

1. WANs interconnect LANs over wide geographical areas such as between cities or continents.
2. WANs are usually administered by multiple service providers.
3. WANs typically provide slower speed links between LANs.

Question 3

GEOGRAPHICALLY

Describe MANs

Answer 3

span distances up to 100 miles.
• These networks are frequently used as links between office buildings that are located throughout a city.
• not owned by a single organization. Rather, it is owned either by a group of organizations or by a single network service provider that provides network services for a fee.

Question 4

GEOGRAPHICALLY

Describe PANs

Answer 4

Network that connects devices, such as mice, keyboards, printers, smartphones, and tablets within the range of an individual person. PANs are most often connected with Bluetooth technology

Question 5

OWNERSHIP

Classify networks based on ownership

Answer 5

Public- A network to which anyone can connect eg the internet
Private- Any network to which access is restricted

Question 6

INFRASTRUCTURE

Describe client/server

Answer 6

In this design, a small number of computers are designated as centralized servers and given the task of providing services to a larger number of user machines called clients

A server computer provides a link to the resources
necessary to perform any task. Client computers normally request and receive information over the network

Question 7

INFRASTRUCTURE

Describe peer to peer

Answer 7

A group of computers are linked together with equal permissions and responsibilities for processing data

Question 8

INFRASTRUCTURE

Give the advantages and disadvantages of P2P

Answer 8

ADVANTAGES

1. Easy to set up
2. Less complex
3. Lower cost since network devices and dedicated servers are not required
4. Can be used for simple tasks such as transferring files

DISADVANTAGES

1. No centralized administration
2. Not as secure
3. Not scalable
4. Slow performance since devices act as both clients and servers

Question 9

INFRASTRUCTURE

Describe thin client and SAN infrastructures

Answer 9

Thin client- All software and resources are installed on a central device and dumb terminals are used
Storage Area Network- For sharing data

Question 10

SIZE

Describe the internet and give its characteristics

Answer 10

A worldwide system of interconnected computer networks.

CHARACTERISTICS
• Each packet is individually routed
• No time guarantee for delivery
• No guarantee of delivery in sequence
• No guarantee of delivery at all!
• If packet is re-transmitted too soon duplicate packets are formed.

Question 11

SIZE

Describe the intranet

Answer 11

-A private network that is contained
within an enterprise. It may consist of many interlinked LANs and also use leased lines in the WAN
• An intranet uses TCP/IP, HTTP, and other Internet protocols and in general looks like a private version of the Internet.-
-With tunneling, companies can send private messages through the public network, using the public network with special encryption/decryption and other security safeguards.

Question 12

SIZE

Describe extranet

Answer 12

A controlled private network that allows access to partners, vendors and suppliers or an authorized set of customers

Question 13

REPRESENTATION

Classify networks according to different representations

Answer 13

Logical- A logical network is a portion of a physical network that connects two or more logical network interfaces or devices
Physical-A physical network connects two or more physical network interfaces.

Question 14

TOPOLOGY

Describe bus topology and give its advantages and disadvantages

Answer 14

Each device is connected to a common cable called a bus or backbone, and all communications travel
along this bus.

Advantages

1. It is easy to set up, handle, and implement.
2. It is best-suited for small networks.
3. It is cheap to install.

Disadvantages
1,The cable length limits the number of possible network nodes.
2.When the number of devices connected to the bus increases, the efficiency decreases.
3. High traffic increases load on the bus, and the network efficiency drops.
4.It is heavily dependent on the central bus. A fault in the bus leads to network failure.
5.It is not easy to isolate faults in the network nodes.
6.Each device on the network “sees” all the data being transmitted, thus posing a security risk.

Question 15

TOPOLOGY

Describe ring topology and give its advantages and disadvantages

Answer 15

Each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node

Advantages

1. A central server is not required for management.
2. The traffic is unidirectional and the data transmission is high-speed.
3. In comparison to a bus, a ring is better at handling loads.
4. The adding or removing of network nodes is easy, as the process requires changing only two connections.
5. The configuration makes it easy to identify faults in network nodes.

Disadvantages

1. The failure of a single node in the network can cause the entire network to fail.
2. The movement or changes made to network nodes affect the entire network’s performance.
3. Data sent from one node to another has to pass through all the intermediate nodes. This makes the transmission slower in comparison to that in a star topology. The transmission speed drops with an increase in the number of nodes.
4. There is heavy dependency on the wire connecting the network nodes in the ring.

Question 16

TOPOLOGY

Describe mesh topology and give its advantages and disadvantages

Answer 16

The mesh network requires that each node have more
than one connection to the other nodes.
• Connects all devices to each other.

Advantages

1. The arrangement of the network nodes is such that it is possible to transmit data from one node to many other nodes at the same time.
2. The failure of a single node does not cause the entire network to fail as there are alternate paths for data transmission.
3. It can handle heavy traffic, as there are dedicated paths between any two network nodes.
4. Point-to-point contact between every pair of nodes, makes it easy to identify faults.

Disadvantages

1. Many connections serve no major purpose. This leads to redundancy of many network connections.
2. A lot of cabling is required. Thus, the costs incurred in setup and maintenance are high.
3. Owing to its complexity, the administration of a mesh network is difficult.

Question 17

TOPOLOGY

Describe star topology and give its advantages and disadvantages

Answer 17

each device is connected directly to a central network switch. Whenever a node sends a message, it is routed to the switch, which then passes the message along to the intended recipient

Advantages

1. Due to its centralized nature, the topology offers simplicity of operation.
2. It also achieves isolation of each device in the network.
3. Adding or removing network nodes is easy, and can be done without affecting the entire network.
4. Due to the centralized nature, it is easy to detect faults in the network devices.
5. As the analysis of traffic is easy, the topology poses lesser security risk.
6. Data packets do not have to pass through many nodes, like in the case of a ring network. Thus, with the use of a high-capacity central hub, traffic load can be handled at fairly decent speeds.

Disadvantages

1. Network operation depends on the functioning of the central hub. Hence, central hub failure leads to failure of the entire network.
2. The number of nodes that can be added, depends on the capacity of the central hub.
3. The setup cost is quite high.

Question 18

TOPOLOGY

Describe tree topology and give its advantages and disadvantages

Answer 18

Each device is connected to a central node, either directly or through one or more other devices.
• The central node is connected to two or more subordinate nodes that in turn are connected to other subordinate nodes, and so forth, forming a treelike structure.

Advantages

1. Each star segment gets a dedicated link from the central bus. Thus, failing of one segment does not affect the rest of the network.
2. Fault identification is easy.
3. The network can be expanded by the addition of secondary nodes. Thus, scalability is achieved.

Disadvantages

1. As multiple segments are connected to a central bus, the network depends heavily on the bus. Its failure affects the entire network.
2. Owing to its size and complexity, maintenance is not easy and costs are high. Also, configuration is difficult in comparison to that in other topologies.
3. Though it is scalable, the number of nodes that can be added depends on the capacity of the central bus and on the cable type.

Question 19

Differentiate between a physical and logical topology

Answer 19

A logical topology is how devices appear connected to the user. A physical topology is how they are actually interconnected with wires and cables.

Question 20

Using Illustrations describe Campus Area Networks

Answer 20

A network that covers an educational or corporate campus. Examples include elementary schools and university campuses. Larger than a LAN