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COE Chapter 2: Network Models - Coggle Diagram
COE Chapter 2: Network Models
Layered tasks
Takes a task (like data communication), and breaks it down into a series of sub-tasks, activities, layers or steps.
Layered Architecture
Related networking functions are grouped together into distinct groups, & those groups become the layers
Each layer defines a family of functions distinct from those of the other layers.
Networking model
A comprehensive set of documents
Each document describes one small function required for a network.
Collectively, these documents define everything that should happen for a computer network to work.
Some documents define a protocol
Which is a set of logical rules that devices must follow to communicate
Other documents define some physical requirement for networking.
Two Models
TCP/IP Network Model (5-layer)
Network
Focuses on delivering data over the entire path from the original sending computer to the final destination computer
e.g. the major protocol is: IP, ICMP
IP provides addressing & routing
Data Link
Focuses on sending data over one type of physical link:
e.g. 802.11 (wi-fi)
Transport
e.g. most common porotcols: TCP, UDP
provides services to the application layer protocols that reside one layer higher in the model
e.g. error recovery; reliable delivery of entire message
Physical
Focuses on how to transmit bits over the physical medium
Ethernet
Application
HTTP, POP3, SMTP
HTTP, defines how web browsers can pull the content of a web page from a web server
Provides services to the application software running on a computer.
Doesn't define the application, only the services
Provides an interface b/w software running on a computer & the network itself
OSI (open system interconnection) model (7-layer)
Both models breaks the communication functions into a small number of categories, called layers.
Each layer, include specific protocols and standards that relate to that category of functions.