What are the responsibilities of the network layer?

Question

What are the responsibilities of the network layer?

Answer 1

The network layer responds to the service requests that are sent from the transport layer and then issues those service requests to the data link layer. It also directs where the information will travel by obtaining the proper address of the end user by detecting where on a network or sub-network the end user’s IP is located. One of the functions that the network layer is responsible for is the connections model. This means the connection between an IP and a sending network. The IP is connectionless and does not have to send an acknowledgement. This layer determines where the address is of a host computer on a network.

Answer 2

Duties Of Network Layer

Answer 3

A change is a "save and forward" community gadget, that figures out the place the packets are to bypass to, and sends it to those ports basically. A router materials translation between 2 networks, in many circumstances a LAN and the internet. It helps using many desktops on the LAN component, and interprets all their web site visitors to the only public IP which you get from the ISP. It keeps music of all of it... maximum cutting-part routers now contain a 4 port change equipped into them (mixed).

Answer 4

Hey network layer is the most essential layer of osi model as it deals with the data transferring from on to another place...

The network layer is the third layer out of seven in the OSI model and the third layer out of five in the TCP/IP model. In the TCP/IP reference model it is called the Internet layer. In all of the models, the network layer responds to service requests from the transport layer and issues service requests to the data link layer.



In essence, the network layer is responsible for end to end (source to destination) packet delivery, whereas the data link layer is responsible for node to node (hop to hop) frame delivery.



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, and error control functions.



The network layer deals with transmitting information all the way from its source to its destination - transmitting from anywhere, to anywhere. Here are some things that the network layer needs to address:



Is the network connection-oriented or connectionless?

For example, snail mail is connectionless, in that a letter can travel from a sender to a recipient without the recipient having to do anything. On the other hand, the telephone system is connection-oriented, because the other party is required to pick up the phone before communication can be established. The OSI Network Layer protocol can be either connection-oriented, or connectionless. The IP Internet Layer (equivalent to OSI's Network Layer) supports only the connectionless Internet Protocol (IP); however, connection-oriented protocols, such as TCP, exist higher in the stack by enforcing reliability constraints through timeouts and resending packets.

What are the Global Addresses?

Everybody in the network needs to have a unique address which determines who he is. This address will normally be hierarchical, so you can be "Fred Murphy" to Dubliners, or "Fred Murphy, Dublin" to people in Ireland, or "Fred Murphy, Dublin, Ireland" to people anywhere in the world. On the internet, these addresses are known as IP Addresses.

How do you forward a message?

This is of particular interest to mobile applications, where a user may rapidly move from place to place, and it must be arranged that his messages follow him. Version 4 of the Internet Protocol (IPv4) doesn't really allow for this, though it has been hacked somewhat since its inception. Fortunately, the forthcoming IPv6 has a much better designed solution, which should make this type of application much smoother.

Answer 5

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 fragmentation and reassembly, and report delivery errors. Routers operate at this layer—sending data throughout the extended network and making the Internet possible. 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). It manages the connectionless transfer of data one hop at a time, from end system to ingress router, to router to router, and from egress router to destination end system. It is not responsible for reliable delivery to a next hop, but only for the detection of errored packets so they may be discarded. When the medium of the next hop cannot accept a packet in its current length, IP is responsible for fragmenting into sufficiently small packets that the medium can accept it.



A number of layer management protocols, a function defined in the Management Annex, ISO 7498/4, belong to the network layer. These include routing protocols, multicast group management, network layer information and error, and network layer address assignment. It is the function of the payload that makes these belong to the network layer, not the protocol that carries them.