Network service model - network layer and routing, Computer Networking

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 between  sending  and receiving end  systems.

Lets now  consider  some  possible  services  that the  network  layer  can provide. In the sending  host when  the transport  layer passes a packet to the network  layer  specific services that  could be provided by  network  layer  include:

a.This  service  guarantees that the  packet will eventually arrive at tits destination.

b.Offers uniform  services  various types  of sub network . the sub network  may be defined as a set  of one  or more  intermediate nodes  which  are used  for establishing network  connection between  end systems and provide  routing  and  relaying of frames thought  it.

c.Offers  uniform  addressing and services to LAN and WAN the  network  layer defines  network  addresses which  are being  used by transport enmities to access network services. Each transport entity is a unique network connection end point  identifier  defined by the  network  layer  which  may be independent of addressing required by underlying layer. The  network entities define network  connection and  may also include intermediate nodes which  usually  provide  relaying. The network  connection   over intermediate subnets is known  as a subnet connection and is usually  handled by  underlying protocols.

d.Establishes  control and maintains  a logical  connection between  the transport  layer  entities for exchanging the data  across the network. The network  connection offers  point to point  connection and more than one  network connection may  be defined between  the same  pair of network  addresses. The network  service data units  are transferred transparently between transport  entities over the network connection  and generally do not have  upper  limit  on their  size.

e.The transport  layer can adapt to different types  of sub network  ( it is  independent  of the characteristics of sub network e, g routing  strategies considered topologies and type of the sub network).

f.Offers an acceptable quality of services during  the network  connection  which  in turn  is based on parameters such as residual error rate service availability  throughput reliability etc. It also reports any undetectable error  to the transport layer.

g.Provides sequencing for NDSU over the  network  connection when  requested by transport  entities.

h.Provides both  connection oriented  and connectionless services to the  users.

In connection oriented services a logical connection is set  up between  two transport entities including agreement for the  type of service desired parameters cost priorities transfer of  data in both direction with  appropriate flow control  and finally the termination of the  connection.

On the other  hand  in connectionless service network  layer primitives SEND  and RECEIVE are being  used to  send and receive the packet across the networks. The  users  are responsible for flow  control  and error  control  on their  hosts.

Posted Date: 3/16/2013 2:55:08 AM | Location : United States







Related Discussions:- Network service model - network layer and routing, Assignment Help, Ask Question on Network service model - network layer and routing, Get Answer, Expert's Help, Network service model - network layer and routing Discussions

Write discussion on Network service model - network layer and routing
Your posts are moderated
Related Questions
Question: a) The Systems Administrator of Acme Company performs the backup of the website database file every day at 15:50. The original file location is database.sql. The Ad

Go Back ( GBN) Go back  N ARQ is specific  instance of the  automatic  repeat request protocols  in which  the sending  process continues to send  a number of frames specific

Determine about the proxy servers There are proxy servers that act as good firewall protection for the entire Intranet system. In some cases, firewall comes as a separate serv

The three ways to give login access to the router are by the Console port, auxiliary port, and virtual terminal (Telnet)

Firewalls Firewalls emerged as a new technology in 1990s but its idea was present near two decades back. Historical context of "Firewall" is quite literal. It was in use to des

Internet  Service Provider (ISP) This  supper fast  network  spanning  the world  from  one major  metropolitan area to another  is provided  by a handful of national internet

ICMP is used to send error and control messages. Ping uses ICMP to carry the echo-request and echo-reply.

Mesh : This is two dimensional networks.  In this all processing elements are organised in a two dimensional grid. The processor in the row i and column j are indicated by PE i .

Control This field  defines 6 different  control  bits or  flags. These bits  enable flow  control  connection  establishment  and termination connection abortion and the mode

Question : a) Describe the following core components of a cellular based network: i) Cell ii) MSC iii) HLR & VLR iv) PSTN b) Explain why frequency reuse is consi