Transcript 1.2 Types of Network Topologies

OBJECTIVE:
o
Describe various network topologies
o
Discuss the role of network devices
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Understand Network Configuration Factors to deploy a new network
1.0 NETWORK TOPOLOGIES
 Physical layout of computers, cables and other components on the network
 Also referred as:
 Physical Layout
 Design
 Diagram
 Map
1.1 Purpose of Network Topology
 How computers communicate on the network
 Different topology – Different communication method
1.2 Types of Network Topologies
 Bus
 Star
 Ring
1.2.1 Bus
 Terminals are connected in a row along a single cable
 Single cable is also known as Trunk, Backbone or Segment
1.2.1.a How it works?
 Sending host sends the data to all computers in network
 Only that node accepts the data whose address matches the destination code
 Only one computer can send data at one time
 Network performance affects as number of nodes increases
 If one computer fails it does not affect rest of the network
 Terminators are installed at each end to absorb free signals (signal bouncing)
 Network becomes down if one end is empty or cable is physically cut
1.2.2 Star
 Terminals are connected by a cable segment to a central device
 Central Device can be a HUB or Switch
1.2.2.a How it works?
 Sending host sends the data to central device
 Central Device sends the data to receiving host
 If central device fails, the entire network becomes down
 If one computer or one cable fails, it does not affect rest of the computers
1.2.3 Ring
 Terminals are connected on a single circle of cable
 No terminated ends
1.2.3.a How it works ?
 Signals travel in a loop in one direction and pass through each computer
 Each computer acts like a repeater unlike passive bus topology
 Failure of one computer can impact the entire network
 Ring topology use TOKEN PASS technology
2.0 NETWORK DEVICES
PURPOSE OF NETWORK DEVICES:
Regulate the speed at which network information travels
 Manage flow of traffic, opening, closing and directing of traffic
 Protect sensitive information
2.1 Network Interfaces
 Network Interface Card (NIC) is a device used to connect computers, printers
and other peripherals to a network
 Sending NIC --- Parallel into serial form
 Receiving NIC --- Serial into Parallel form
 Speed is measured in bps
 Each NIC has a unique MAC address
 Each NIC is assigned an IP Address by Network Administrator
2.2 HUB
 HUB stands for Hybrid Universal Bus
 A small device gathers the signals from each individual device optionally
amplifies, and sends the data to all other connected devices
 All devices connected to a HUB share the bandwidth of network
 More devices connected to a HUB, lower the network performance
 12 or 24 ports available in standard HUB
 Speed is measured in bps
2.3 Switch
 Switch works exactly in the same way as HUB except:
 It does not broadcast
 It does not interfere network bandwidth
 8, 12, 24 Ports are usually available
 Speed is measured in bps
 Must be compatible with other network devices
2.4 Routers
 Routers connect two or more networks of different design
 Find the best path (route) to transmit data
 Routers can be programmed to define traffic rules
 Expertise are required to configure routers
2.5 Firewalls
 A device (combination of hardware and software) that protects unauthorized
access to a network
Types of Firewalls
 Packet Screening Firewalls
 Proxy Servers
 State full Inspection Proxies
3.0 NETWORK CONFIGURATION FACTORS
i. Choosing the Network Type / Utilization
• Peer to Peer
• Server Based Networking
ii. Choosing the Network Topology / Performance
• Bus
• Star
• Ring
iii. Choosing the Communication Media / Performance
• Physical Media
• Wireless Media
• Light Emitted Media
iv. Future Considerations / Flexibility
v. Cost
vi. Maintenance