Found 496 Articles for Computer Engineering

The architecture of the Internet is ever-changing due to continuous changes in the technologies as well as the nature of the service provided. The heterogeneity and vastness of the Internet make it difficult to describe every aspect of its architecture.The overall architecture can be described in three levels −Backbone ISP (Internet Service Provider)Regional ISPsClientsThe following diagram shows the three levels −Backbone ISP (Internet Service Provider) − Backbone ISPs are large international backbone networks. They are equipped with thousands of routers and store enormous amounts of information in data centers, connected through high bandwidth fiber optic links. Everyone needs to connect ... Read More

The Internet has become a very important part of our daily lives and has its applications in wide areas.Some of the areas in which Internet is used are −CommunicationsEducation and researchInstant messagingOnline business and shoppingOnline financial servicesFile and data sharingDeveloping collaborative softwareDesign and development of applications and computing environmentsContent managementEntertainmentSocial networkingStorage of dataOnline publishing and digital newspapersGovernance and politicsDiscussion forumsCharityAudio and video conferencingTelephony (VoIP)The Internet offers a number of services, as enlisted below −Communication services - e.g. electronic mail, telnet, telephony (VoIP), newsgroups, and instant messagingInformation retrieval services – e.g. FTP, and GopherWorld Wide Web (www) servicesRead More

Some of the prominently used networks in today’s world are −InternetIEEE 802.11 for Wireless LANRFID and Sensor NetworksInternetInternet is a global collection of vast number of dissimilar networks that are interconnected together. Internet uses the TCP/IP protocol and provides varied services. The networks forming the Internet may be private, public, academic, commercial or government, but Internet as a whole is not controlled by any one organization. Internet uses a wide range of networking technologies which are being continually upgraded.The traditional services provided by the Internet were electronic mail, file sharing, and hyperlinked documents. The passage of time has been witnessing ... Read More

The advantages of TCP/IP protocol suite areIt is an industry–standard model that can be effectively deployed in practical networking problems.It is interoperable, i.e., it allows cross-platform communications among heterogeneous networks.It is an open protocol suite. It is not owned by any particular institute and so can be used by any individual or organization.It is a scalable, client-server architecture. This allows networks to be added without disrupting the current services.It assigns an IP address to each computer on the network, thus making each device to be identifiable over the network. It assigns each site a domain name. It provides name and ... Read More

The advantages of the OSI model areIt is a generic model and acts as a guidance tool to develop any network model.It is a layered model. Changes are one layer do not affect other layers, provided that the interfaces between the layers do not change drastically.It distinctly separates services, interfaces, and protocols. Hence, it is flexible in nature. Protocols in each layer can be replaced very conveniently depending upon the nature of the network.It supports both connection-oriented services and connectionless services.The disadvantages of the OSI model areIt is purely a theoretical model that does not consider the availability of appropriate ... Read More

Similarities between OSI and TCP / IP Reference ModelsBoth the reference models are based upon layered architecture.The layers in the models are compared with each other. The physical layer and the data link layer of the OSI model correspond to the link layer of the TCP/IP model. The network layers and the transport layers are the same in both the models. The session layer, the presentation layer and the application layer of the OSI model together form the application layer of the TCP/IP model.In both the models, protocols are defined in a layer-wise manner.In both models, data is divided into ... Read More

The application layer is the highest abstraction layer of the TCP/IP model that provides the interfaces and protocols needed by the users. It combines the functionalities of the session layer, the presentation layer and the application layer of the OSI model.The functions of the application layer are −It facilitates the user to use the services of the network.It is used to develop network-based applications.It provides user services like user login, naming network devices, formatting messages,  and e-mails, transfer of files etc.It is also concerned with error handling and recovery of the message as a whole.This layer uses a number of protocols, ... Read More

The transport layer is responsible for error-free, end-to-end delivery of data from the source host to the destination host. It corresponds to the transport layer of the OSI model.The functions of the transport layer are −It facilitates the communicating hosts to carry on a conversation.It provides an interface for the users to the underlying network.It can provide for a reliable connection. It can also carry out error checking, flow control, and verification.The protocols used in this layer are −Transmission Control Protocol, TCP − It is a reliable connection-oriented protocol that transmits data from the source to the destination machine without ... Read More

The Internet layer is responsible for logical transmission of data packets over the internet. It can be compared to the network layer of the OSI model.The main functions of the internet layer are −It transmits data packets to the link layer.It routes each of the data packets independently from the source to the destination, using the optimal route.It reassembles the out-of-order packets when they reach the destination.It handles the error in transmission of data packets and fragmentation of data packets.The protocols used in this layer are −Internet Protocol, IP − It is a connectionless and unreliable protocol that provides a ... Read More

The host-to-network layer is the lowest layer of the TCP/IP model and is concerned with the physical transmission of data. It is also called a network interface layer or link layer. It can be considered as the combination of physical layer and data link layer of the OSI model.The functions of this layer are −It defines how bits are to be encoded into optical or electrical pulses.It accepts IP packets from the network layer and encapsulates them into frames. It synchronizes the transmission of the frames as well as the bits making up the frames, between the sender and the ... Read More