Compare and contrast tcp/ip and osi models

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Compare and contrast tcp/ip and osi models

By | September 2012
Page 1 of 7
The two, OSI and TCP/IP are Standardized Protocol Architectures developed specifically for: 1.Devices to communicate
2.Vendors to have more marketable products
3.Customers to insist on standards based equipment
The OSI is a reference model whilst TCP/IP is the suite which is the most widely used. Description of Open Systems Interconnection (OSI Model)
Developed by the International Organization for Standardization (ISO) It is made up of seven layers and each layer:
1. performs a subset of the required communication functions 2. relies on the next lower layer to perform more primitive functions 3.provides services to the next higher layer
4.Changes in one layer should not require changes in other layers

The layers can be summarized as overleaf:

Layer FunctionsMain features
1PhysicalConcerned with transmission of unstructured bit stream over physical medium; deals with the mechanical, electrical, functional, and procedural characteristics to access the physical mediumPhysical interface between devices 1.Mechanical

2.Electrical
3.Functional
4.Procedural
2Data linkProvides for the reliable transfer of information across the physical link; sends blocks (frames) with the necessary synchronisation, error control and flow controlMeans of activating, maintaining and deactivating a reliable link Error detection and control

Higher layers may assume error free transmission
3NetworkProvides upper layers with independence from the data transmission and switching technologies used to connect systems; responsible for establishing, maintaining and terminating connectionsTransport of information Higher layers do not need to know about underlying technology Not needed on direct links

4TransportProvides reliable, transparent transfer of data between end points; provides end-to-end error recovery and flow control.Exchange of data between end systems Error free
In sequence
No losses
No duplicates
Quality of service

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