Network topology

LAN

Local Area Network

Local Area Network (LAN)

A number of computing devices on a single site or in a single building, connected together by cables

Network topology

The arrangement of the elements of a communication network

Bus topology

All computers connected to a single cable, the ends of which are plugged into a terminator

Star topology

All computers connected to a central node, which may be a switch or computer acting as a router to transmit messages

Which topology is more expensive to install and why?

Star topology - requires more cable and additional hardware (hub/switch)

Which topology is less expensive to install and why?

Bus topology - requires less cable and no additional hardware

Which topology is more robust?

• Both have central point of failure (bus: cable, star: central device)

• Generally, star topology:

  • If one cable fails, only one station affected - easy to isolate faults

  • But, if central device fails, network data can no longer be transmitted to any node

Which topology is more performant with heavy traffic?

Star topology - consistent performance even when network is being heavily used

How does a star network work?

Switch keeps a record of the unique MAC address of each device on the network and can identify which particular computer on the network it should send the data to.

How does a logical bus network work?

• Network signals are sent through the main cable to reach all connected devices (or station)

• Traffic generated by each station has equal priority

• Each message contains a destination address that identifies its intended recipient

• Only the intended recipient actually accepts and processes the message

Physical topology

The actual design layout of a network

Logical topology

The shape of the path the data travels in a network, describing how components communicate across the physical topology

The physical and logical topology of a network are _____ of each other

Independent

MAC address

Media Access Control address

Media Access Control (MAC) address

Unique address identifying a NIC, which is assigned and hard-coded by the manufacturer

NIC

Network Interface Card

How many bits are assigned to a MAC address?

48

How are MAC addresses written?

As 12 hex digits grouped into pairs, separated by hyphens (e.g. 00-09-5D-E3-F7-62)