References model : Protocol standard is also know as a reference model. It has two types ,These
i) OSI & ii) TCP/IP
OSI : The full form of OSI is the open System interconnection. OSI deals with connect opebn systems that is systems that are open communication with other system. It has seven phases/layer for communicating data from source to destination, this is why it is called seven layer model.
1) Application
2) Presentation
3) Session
4) Transport
5) Network
6) Data Link
7) Physical
Fig : OSI Layer
1) Physical layer : The layer od OSI that co-ordinates the function required to transmit a bit over a physical medium called physical layer. It deals with the mechanical and electrical specification of devices.
Characteristics :
i) Physical characteristics of interfaces & media
ii) It represents the data
iii) Data rate
iv) Synchronization of bits
v) Physical topology
vi) Transmission mode
vii) Line configuration
2) Data Link layer : The layer of OSI that transforms the physical layer to a reliable link is called data link layer.
Characteristics :
i) It deals with framing
ii) Physical addressing
iii) Flow control
iv) Error control
v) Access control
vi) Traffic regulation mechanism
3) Network Layer : The layer that responsible source to destination to delivery of packet
multiple network is called network layer.
Characteristics :
i) Logical addressing
ii) Routing
iii) Connecting different network.
4) Transport Layer : The layer of OSI that is for process to process delivery of the entire message is called transport layer.
Characteristics :
i) Service point addressing
ii) Segmentation and re-assembly
iii) Connection control
iv) Flow control
v) Error control
vi) Port control
5) Session Layer : The Layer of OSI that allows of different machine to establish session among them is called session layer.
Characteristics :
i) Provides enhanced service to the u
ii) It allows the user to log into a remain time sharing system.
iii) It means dialogue control among the devices
iv) It allows traffic to go in both direction at the same time
v) Provides token management facility
vi) Synchronization of the devices.
6) Presentation Layer : The layer which is concerned with the semantics of the information exchange between the two systems is called presentation layer.
Characteristics :
i) Translation
ii) Encryption
iii) Compression
iv) Relation between the layers
7) Application Layer : The layer that provides human or user to access the network is called application layer.
Characteristics :
i) mail-Service
ii) File transfer/management
iii) Remote log in
iv) Directory service
v) Access of WWW.
Comments
Post a Comment