Encryption is a technique to hide data from unauthorized persons by encoding data not to be viewed and modified. Data encryption involves converting the data into encrypted data called cipher text using a mathematical formula called an algorithm.These algorithms generate a key and then encapsulate the message with this key. There are two types of encryptions as asymmetric and symmetric, are in vogue.The presentation layer deals with the translation, encryption/decryption, authentication and compression, which are explained below−TranslationIt changes the complex data structures used by an application string, integers, structures, etc., into a byte stream that may be transmitted across the ... Read More

Multimedia is a set of more than one media element used to produce a concrete and more structured communication method. In other words, multimedia is the simultaneous use of data from different sources. These sources in multimedia are known as media elements.Multimedia is the holy grail of networking. It brings vast technical challenges in providing (interactive) video on demand to every home and equally immense profits out of it. Multimedia is just two or more media. Generally, the term multimedia means the combination of two or more continuous media. In practice, the two media usually are audio and video.Elements of ... Read More

Quality of Service (QOS) determines a network's capability to support predictable service over various technologies, containing frame relay, Asynchronous Transfer Mode (ATM), Ethernet, SONET IP-routed networks. The networks can use any or all of these frameworks.The QOS also provides that while supporting priority for one or more flows does not create other flows fail. A flow can be a combination of source and destination addresses, source and destination socket numbers, session identifier, or packet from a specific application or an incoming interface.The QOS is primarily used to control resources like bandwidth, equipment, wide-area facilities etc. It can get more efficient ... Read More

Congestion causes choking of the communication medium. When too many packets are displayed in a method of the subnet, the subnet's performance degrades. Hence, a network's communication channel is called congested if packets are traversing the path and experience delays mainly over the path's propagation delay. There is two congestion control algorithm which is as follows: Leaky Bucket The leaky bucket algorithm discovers its use in the context of network traffic shaping or rate-limiting. The algorithm allows controlling the rate at which a record is injected into a network and managing burstiness in the data rate. ... Read More

IPv4 supports various types of addressing modes which are as follows−UnicastIt is created to a single network interface located on a specific subnet and facilitates one to-one communication. This is a unique address worldwide for the identification of a machine on the network.Subnet prefix: The subnet prefix is a network identifier or network address portion of an IP unicast address. It must be noted that all nodes on the corresponding physical or logical subnet must help the same subnet prefix, which eventually turns into unique within the entire TCP/IP network.Host ID: The host ID, a host address area of an ... Read More

IPv4 addresses are merely used as identifiers, which operate at the network layer to identify IP packets source or destination. The version of IP that is in use is known as IPv4. In this version, every node on the Internet can have one or more interfaces, and we are needed to recognize each of these devices with a specific address assigned to each of them. It represents that each node is created one or more IP addresses to conjure TCP/IP. These are logical addresses and include 32 bits.IP addresses are defined using binary notation with a 32-bit long string. Dotted ... Read More

Each router on the network supports a routing table in memory that may be simple or complex. In the simplest form, the table consists of pairs of IP addresses.When the originating station involves that the intended destination is directly reachable, the frame is sent immediately to the frame's destination IP address. In such a situation, a unique address occurs in the routing table known as Default Gateway Address.The routing decisions depend on the following points:The destination IP address and router IP are concealed to decide if the incoming packet Notes is to be forwarded to another network or not. If ... Read More

Connection-Oriented ServicesIn a connection-oriented service, each packet is related to a source/destination connection. These packets are routed along a similar path, known as a virtual circuit. Thus, it provides an end-to-end connection to the client for reliable data transfer.It delivers information in order without duplication or missing information. It does not congest the communication channel and the buffer of the receiving device. The host machine requests a connection to interact and closes the connection after the transmission of the data.Mobile communication is an example of a connection-oriented service.Connectionless-ServiceIn connectionless service, a router treats each packet individually. The packets are routed ... Read More

Hub is a unique device used to enhance a network by enabling increased workstations in the network.The three main types of Hubs are as follows−Passive HubPassive hubs do not include any computerized elements, and they do not procedure the data signal at all. The main goal of a passive hub is to connect the signals from various network cable segments. All devices connected to a passive hub take all the packets that develop through the hub.One example of the passive hub is the punch down block consisting of a plastic box with different connectors (mostly RJ 45). This hub is ... Read More

The B-ISDN (broadband integrated services digital network) is a virtual circuit-switched network that can use high-speed packet switching services. The B-ISDN will use a flexible multiplexing format called ATM (asynchronous transfer mode).B-ISDN services are classified into interactive and distribution services. Interactive services contain the bidirectional flow of user information between two subscribers or between a subscriber and a service provider.Interactive servicesThe interactive services are further divided into three sub-categories which are as follows−ConversationalConversational service involves the real-time exchange of information such as sound, video, data or entire documents. Examples include video-telephony, video-conference, and high-speed data transfer. Video-telephony is like the ... Read More