What are OSI layers?

Answer Posted / tej

Application
(Layer 7)
This layer supports application and end-user processes.
Communication partners are identified, quality of service is
identified, user authentication and privacy are considered,
and any constraints on data syntax are identified.
Everything at this layer is application-specific. This layer
provides application services for file transfers, e-mail,
and other network software services. Telnet and FTP are
applications that exist entirely in the application level.
Tiered application architectures are part of this layer.

Presentation
(Layer 6)
This layer provides independence from differences in data
representation (e.g., encryption) by translating from
application to network format, and vice versa. The
presentation layer works to transform data into the form
that the application layer can accept. This layer formats
and encrypts data to be sent across a network, providing
freedom from compatibility problems. It is sometimes called
the syntax layer.

Session
(Layer 5)
This layer establishes, manages and terminates connections
between applications. The session layer sets up,
coordinates, and terminates conversations, exchanges, and
dialogues between the applications at each end. It deals
with session and connection coordination.

Transport
(Layer 4)
This layer provides transparent transfer of data between end
systems, or hosts, and is responsible for end-to-end error
recovery and flow control. It ensures complete data transfer.

Network
(Layer 3)
This layer provides switching and routing technologies,
creating logical paths, known as virtual circuits, for
transmitting data from node to node. Routing and forwarding
are functions of this layer, as well as addressing,
internetworking, error handling, congestion control and
packet sequencing.

Data Link
(Layer 2)
At this layer, data packets are encoded and decoded into
bits. It furnishes transmission protocol knowledge and
management and handles errors in the physical layer, flow
control and frame synchronization. The data link layer is
divided into two sub layers: The Media Access Control (MAC)
layer and the Logical Link Control (LLC) layer. The MAC sub
layer controls how a computer on the network gains access to
the data and permission to transmit it. The LLC layer
controls frame synchronization, flow control and error checking.

Physical
(Layer 1)
This layer conveys the bit stream - electrical impulse,
light or radio signal -- through the network at the
electrical and mechanical level. It provides the hardware
means of sending and receiving data on a carrier, including
defining cables, cards and physical aspects. Fast Ethernet,
RS232, and ATM are protocols with physical layer components.

Is This Answer Correct ?    18 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is the difference between Third-party BPO and Primary BPO (Please understand the question and post answer to my site sweetlittleheart25@yahoo.com)

2168


i have received my call caler till now what should i do

1789


Why do you want to work in a call center?

770


How would you teach a blind person to withdraw her credit card account on an automated teller machine?

1743


what will join in my company?

1804






1.6. Tell me something about your happiest day of your life.

3133


Why doesn’t u go for technical one....as u r doing technical course from NIIT.

2036


Dear All, We have running a esteemed consultancy [FOCUS CONULTANCY] in vadapalani. So any candidate who is interested workin with international & domestic call centre. Our biggest strength is our team work. We placed large number of candidates in international call centre. So, interested candidates pls mail your resume to hari@focusconsultancy.in or please walk in to our office at Focus Consultancy, #11, First Main Road, Vengishwarar Nagar, Vadapalani, chennai - 26. Ph.32462178. Landmark (near to vadapalani murugan temple)&(straight road from vengishwarar temple)&(near to Vijay pharmacy).

1962


Why are like to work in my company?

2123


What you would like to wear traditional or western ?

3137


What is off-shore outsourcing?

798


tell me something about data analyst

2060


can any 1 say how much % is eligible for wipro bpo?

2955


all general question related bpo and self

2138


what is the actual work profile of a process associate in a bpo??

15946