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Introduction to data communication - Coggle Diagram
Introduction to data communication
Efficiency of communication systems
Jitter
Delay on sendind/receiving data packets, what leads to unstable quality of real-time services like videoconferencing
Delivery
A communication system must have ways to deliver data and information
Synchronization
Deliver data with no delay or the minimum delay possible
Precision
All the data must be correct and precise, with no deviation neither alteration
5 components of data communication
Sender
Receiver
Medium
Message
Protocol
It is like the language between the two beings in communication - a SET of rules
Types of Representation of Data
Audio
Is the most different representation of data
It needs to be converted to analog signal, but this signal is uninterrupted and continuous
Video
Continuous stream
Set of many images showed so quickly that it looks like movement
Text
Characters are just converted to binary as the convention says to. The most used convention is
Unicode
, from which the first 127 characters forms the ASCII table
Number
It is directly and mathematically converted to binary
Image
It is made by pixels (picture element)
Pixels are sets of bits and the size of the arrangement of bits will depend on how many colors will be represented
RGB and YCM are two different patterns to set pixels to binary
Data flow
Simplex
One-handed way to communication - one always send and the other always receive
Half-Duplex
Both of them can send or receive, but it happen just one at a time
Full-Duplex or just Duplex
Synchronous communication
The capacity of the midway needs to be divided between the sending and receiving
Network
It is a set of devices able to communicate with all the other devices on the net through a medium like a cable, the air or optical fibers. Each device is also called a node of the network..
Network criteria
Performance
How much information does the medium carry and how much do the computers process.
It depends on the elements on the network
It is measured by delays and throughput
Security
Against attackers or malicious people/programs and also against unauthorized people accessing that information
Reliability
Or availability, it remains at keeping all things working all the time needed
Network components fail rates
It is measured by availability and robustness
Physical structure
Types of connections
Peer-to-peer
One device directly connected to the other
Multipoint
Multiple receptor at a single streaming
Topology
Mesh
All devices within network are connected between themselves. That's the most expensive topology
Ring
It uses a repeater
Star
Usually use Hub to connect a lot of devices in a hierarchy structure
Bus
Uses a bus
It is controlled by private enterprises, not by any government
ISPs
Internet Service Provider
There are main ISPs, regional ISPs and national ISPs
National ISPs
Backbone networks controlled by private enterprises
NAP - Network Access Point
Big networks made up by smaller ones connected through switching stations so that people can connect to them and consequently to the internet
Peering points
Private switching stations to connect some of those contriller enterprises between themselves
They usually work at a high transmission rate (600Mbps)
Local ISPs
Usually, it is a telecom enterprise, a big company that offers a private network to its employees or even other types of institutions with private networks - usually connected to a local ISP or directly to a National ISP