Network Layer and Routing , Computer Networking

Network Layer and Routing

As discussed in previous  chapters the physical  layer  provides   connection sand services to the  data link  layer while the  data link layer is  connected with the  construction of frames error control  flow  control and the transmission of frames over the physical  circuit connection between  computers or even  between  different types  of networks. The  frames  may have  to go through a number of nodes  ( computer networks ) which  may be connected in different topologies. The  network layer entity uses the services of the data link layer and provides services( routing  of packets relaying congestion control etc) to  its higher layer ( transport) and also to different types of intermediate networks of sub networks. The  primary  function of the  network layer are routing selection of appropriate faults controlling of overloading or congestion of traffic on communication lines. Efficient use of various communication liens, etc. This  layer  manages network layer connections and  provides an end to end reliable packet  delivery mechanism. This  provides user to user connection for  exchange of data between them.

The network  layer in the  OSI model is also known  as the subnet which may  run on  internet  where the network  layer  runs on  interface message  processors. The  transport  layer of  the OSI  model  runs on  the horsts. The control  and management of the network layer are provided by  different  organization in different  countries such as  PTT. At and t etc PTT is very poplar  in European countries and undeveloped countries . thus the network layer  not only  provides  services to the transport layer an different sub networks but also defines an interface and  connection different  hosts and different type of networks.

 shows a simple network  with two  hosts. H1  and H2. And several routers on the  path  between H1 and H2. Suppose that H1. Is  sending  information  to H2.and consider the role  of the  network layer  in these  hosts  and in the intervening grouters. The  network layer in H1 takes segments  from the  transport layer inH1. Encapsulated each  segment  into a datagram ( that  is a network layer packet) and  then starts the datagram's  on their  journey to their  destination that is it sends the datagram's to its  nearby router R1. At the receiving  host H2. The network  receiver  the datagram's from  its nearly  router R2 extracts the transport  layer  segments and delivers the segments up to the transport  layer atH2 the primary  role  of the  routers  is to forward datagram's from input links to  output  links. Note  that the  routers in figure are show  with  a truncated protocols  stack that is  with no  upper layers above the  network  because router  do not run  application  and transport layer  protocols.

Posted Date: 3/13/2013 12:54:12 AM | Location : United States







Related Discussions:- Network Layer and Routing , Assignment Help, Ask Question on Network Layer and Routing , Get Answer, Expert's Help, Network Layer and Routing Discussions

Write discussion on Network Layer and Routing
Your posts are moderated
Related Questions
Define Co-axial cable. A solid central conductor surrounded by insulating material and then by a cylindrical shield woven from fine wires is called as co-axial cable. The shie

Issues with Bridges Connecting Different LANs - Frame format - differences in frame structure, fields used (example Ethernet to Token Ring) - Payload size - size of data en

FRAME FILTERING:  The very important task a bridge operates is frame filtering. If both the destination and source are on the same segment, it does not repeat the frame to the

What are the various security measures A matter of prime concern to companies is the overheads in the form of huge investment on extra hardware and software. It is quite possi

Question 1 Explain GSM digital cellular System model Question 2 Explain cellular Digital Packet Data(CDPD) system with the help of CDPD network reference model Question 3

Network Service Model The network  service  model  defines  the characteristics of end to end  transport of data between  one edge of the  network  to the  other  that is betwe

Routing Table Each  router now  uses the  shortest path tree to construct its routing table . each  router  uses the same algorithm and the same link state  database its own sh

network diagram which must include at least 2router,2bridge and 4 switches and must have different protocols and different cable...?

Simplicity The advantage of this approach is the simplicity  of receiver buffering. The  receiver need not  buffer out of  order packets the sender must maintain the upper an

Determine the Difficulties arise with database connectivity A number of difficulties arise with database connectivity and the company may have to shell out an enormous amount