what is meant by layer 3?

Question

what is meant by layer3 device]
what are the purpose

Answer 1

This refers to the OSI stack model for communication. Layer 3 is the network layer. You can see a description here: http://computing-dictionary.thefreedictionary.com/OSI%20model

Answer 2

The Network layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing functions, and might also perform segmentation/desegmentation, and report delivery errors. Routers operate at this layer—sending data throughout the extended network and making the Internet possible (there also exist layer 3 (or IP) switches). This is a logical addressing scheme – values are chosen by the network engineer. The addressing scheme is hierarchical. The best known example of a layer 3 protocol is the Internet Protocol (IP).

Answer 3

The answer is quite technical, but ill give it a go..

First of all give this link a read..

http://en.wikipedia.org/wiki/OSI_model#Layer_3:_Network_Layer

Now as you can see a network is complicated, and is made from layers just like an onion.

Layer 3 in your home for example, will be your router which routes information from the outside to the individual computers inside your home (if you have more than one :P). So it might recieve some information saying send this to computer 1 and send this to computer 2, so the router obeys as long as it does not break any of the rules that you have told it to go by. Hence why a router make a very good firewall, because if it recieves something it is not expecting (rogue information from a driveby hacker) then it does not send it on.

Good luck if you need any more help then pls message me!!

Answer 4

Layer 3 is the network layer in OSI model. This layer controls the communication of packets using IP addresses routed by routers.

Answer 5

osi model consist of 7 layers. Its starts with physical,data link, network layer,transport,session,presentation and application layer. layer 3 is a network layer, it deal with IP address, packet routing from one network to remote network . device used in layer 3 is Router.

Answer 6

layer 3 devices have the ability to route traffic. it uses defined rules or protocols to determine, logically, where traffic must go. the purpose is to make teh intarweb better.