Computer Engineering Articles - Page 35 of 37

Network StandardsNetworking standards define the rules for data communications that are needed for interoperability of networking technologies and processes. Standards help in creating and maintaining open markets and allow different vendors to compete on the basis of the quality of their products while being compatible with existing market products.During data communication, a number of standards may be used simultaneously at the different layers. The commonly used standards at each layer are −Application layer − HTTP, HTML, POP, H.323, IMAPTransport layer − TCP, SPXNetwork layer −IP, IPXData link layer − Ethernet IEEE 802.3, X.25, Frame RelayPhysical layer −RS-232C (cable), V.92 (modem)Types ... Read More

Ethernet is a set of technologies and protocols that are used primarily in LANs. However, Ethernet can also be used in MANs and even WANs. It was first standardized in the 1980s as IEEE 802.3 standard. Since then, it has gone through four generations, as shown in the following chartStandard Ethernet is also referred to as Basic Ethernet. It uses 10Base5 coaxial cables for communications. Ethernet provides service up to the data link layer. At the data link layer, Ethernet divides the data stream received from the upper layers and encapsulates it into frames, before passing them on to the ... Read More

X.25X.25 is a protocol suite defined by ITU-T for packet switched communications over WAN (Wide Area Network). It was originally designed for use in the 1970s and became very popular in 1980s. Presently, it is used for networks for ATMs and credit card verification. It allows multiple logical channels to use the same physical line. It also permits data exchange between terminals with different communication speeds.X.25 has three protocol layers Physical Layer: It lays out the physical, electrical and functional characteristics that interface between the computer terminal and the link to the packet switched node. X.21 physical implementer is commonly used ... Read More

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

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