Found 1320 Articles for MCA

Wireless LANs are those Local Area Networks that use high frequency radio waves instead of cables for connecting the devices in LAN. Users connected by WLANs can move around within the area of network coverage. Most WLANs are based upon the standard IEEE 802.11 or WiFi.IEEE 802.11 ArchitectureThe components of an IEEE 802.11 architecture are as follows1) Stations (STA) − Stations comprise all devices and equipments that are connected to the wireless LAN. A station can be of two types:Wireless Access Pointz (WAP) − WAPs or simply access points (AP) are generally wireless routers that form the base stations or ... 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

ATM and ATM NetworksATM stands for Asynchronous Transfer Mode. It is a switching technique that uses time division multiplexing (TDM) for data communications.ATM networks are connection oriented networks for cell relay that supports voice, video and data communications. It encodes data into small fixed - size cells so that they are suitable for TDM and transmits them over a physical medium.The size of an ATM cell is 53 bytes: 5 byte header and 48 byte payload. There are two different cell formats - user-network interface (UNI) and network-network interface (NNI). The below image represents the Functional Reference Model of 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

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