What is a Communications Model ?
A communications Model consists of
Source - Generates data to be transmitted
Transmitter - Converts data into transmittable signals
Transmission system - Carries data
Receiver - Converts received signal into data
Destination - Takes incoming data
What is Network Communications ?
- Computer network - an interconnection of computers and computing equipment using either wires or radio waves over small or large geographic distances
- Voice network - a network that transmits telephone signals
Data network - a network that transmits computer data
What is Computer Network ?
Computer Network: A connection between two or more computers to exchange data or provide shared access to resources.
- Node: Any device that can send or receive data via a Network.
Nodes are linked by communications cabling or radio waves.
What is Wireless PAN ?
- Personal Area Network (PAN): Connects computing and other devices in the immediate vicinity of an individual to support the activities of that individual
What is Local Area Networks (LANs) ?
- A LAN (Local Area Network) is a type of computer network where nodes are connected at high speed in a confined geographical area
- Network service area usually limited to a given office area, floor, or building.
- All components of the LAN are commonly owned by the organization that uses it.
What is Metropolitan Are Network (MAN) ?
Medium speed network that connects sites over distances up to 50 miles. Generally used by organizations that have several locations over the same city.
What is Wide area network (WAN) ?
WANs are made up of LANs connected by lower speed long distance links. WANs usually cover a significant geographical area.
What is Network Topology ?
- The physical topology (part of the physical layer) refers to the physical arrangement of a network’s stations, switches, routers, and transmission lines.
- The logical topology (part of the data link layer) describes how the data flows through the physical topology or the actual pathway of the data.
- Different network (and internet) standards specify different topologies.
- The physical and logical topologies are not always the same
What is BUS Topology ?
- All network devices connected to a common cable in logical linear fashion.
- Transmissions are sent along the length of the bus segment.
- Examples: obsolete Ethernet 10Base5 and 10Base2, both using coaxial cable
What is the essential part of A Bus Topology Connecting Stations ?
One long cable (main cable) acts as backbone to link all the devices in a network. Nodes are connected to the bus cable by drop lines and taps (connectors).
What is Ring Topology ?
- Continuous path for data with no logical beginning or ending point.
- Examples: obsolete IBM token ring and FDDI (fiber distributed data interface).
- Each node attaches to a repeater. When a device receives a signal intended for another device, its repeater regenerates the data signal and passes it along, which helps keep the signal from degrading
- Each node attaches to a repeater. When a device receives a signal intended for another device, its repeater regenerates the data signal and passes it along, which helps keep the signal from degrading
- Data frame circulates past all devices
- Destination device recognizes the address and copies the frame.
- Frame continues circulating back to source where it is removed
What is Star Topology ?
- Connection from each device to a central location, usually a hub or switch.
- Most commonly used physical topology
- Failure of one cable does not bring down network
- Examples: Ethernet 10BaseT and 100BaseTX, both using UTP cord.
A Fiber Opic Backbone with Category 5
A Pair of Bridges and Switch Combination ?
A Communications Model ?
A Bus Topology Connnecting Stations
