Communication Network Essay.
Communication network are large system distributed in wide area which are designed to send and receive information from one computer to another computer and this computers are called host. Network achieves this providing a set of rules which in terms of networking are called protocols. This protocols are set for communication which every host should follow and participate. The network is made up of two types of components: Nodes and Communication lines. The nodes manages the network protocol and provides switching capabilities.
Usually a node is a computer itself which operates different network. The communication lines is the route that connects a power house to its base. Examples : copper wire cables, radio waves and telephone lines. Human resources are nowadays dependent on communication through network and their various types and protocols. Human uses this network to exchange information through symbols, signals and speeches and for this type of communication network provides different tools such as radio, television, computer etc. The role of communication network is globally in current era.
Networks are constructed across wide area buildings. Networks may also be citywide and even international, using both cable and air connections. There are three types of major networks . 1> LOCAL AREA NETWORK (LAN) 2> WIDE AREA NETWORK (WAN) 3> METROPOLITAN AREA NETWROK (MAN). 1. LOCAL AREA NETWORK (LAN) Group of computers which all belong to same organizations and which are linked within a small geographic area using a network and often the same technology. Data transfer speeds over a local area network can reach up to 10 Mbps to 1 Gbps.
Local area network can reach as many as users may be 100 or even 1000 users. LOCAL AREA NETWORK is also divides in two small area network. 1> TINY AREA NETWORK (TAN) AND 2> CAMPUS AREA NETWORK (CAN). TINY AREA NETWORK are locally used within the houses and small associations while CAMPUS AREA NETWORK are usually used for schools and universities. LOCAL AREA NETWORK are operated by two different modes * Peer-to-peer – Network in which communication is carried out from one computer to another computer without a central computer and where each computer has the same role *
Client/server – Environment in which a central computer provides a network service to users 2. WIDE AREA NETWORK (WAN) WAN connects multiple local network to one another over great geographic distances. The speed available on Wide network depends on the cost of connection the buyer spends on it. WAN usually operate using routers. Big corporation and business owns wide area network for the company users. 3. METROPOLITAN ARE NETWORK (MAN) Connects multiple geographically near by LANS to one another at high speeds.
Thus a MAN lets two remote modes communicate as if they were part of some local area network. MAN is made from switches or routers connected to one another with high speed links. ACCESS RESTRICTION When it comes to network then how can one forget about the restrictions one has accessing it. There are two kinds of restriction. 1) Public Network 2) Private Network. * Public network – The networks that are publically visible to the internet and also some of the network can be easily access to the public. By this it doesn’t mean that public can have access to the network of the company.
This network are generally used by the public but may require registration fees * Private network – In private network the device cannot access directly to the network nor they can directly communicate to them. Networks that are maintained and used by banks, hospital, airlines etc. OSI MODEL:- The International Standards Organization (ISO) has developed a reference model for network design called the Open Systems Interconnection (OSI). It proposes a seven-layer architecture for networks 1. Physical layer 2. Data-link layer 3. Network layer 4. Transport layer 5. Session layer 6.
Presentation layer 7. Application layer The seven layer represents the protocol architecture for the communications components of host but the nodes in the network applies to only first three lower layers and the reason behind the node using only lower three layers is that the upper four layers are not capable to the task of communication between the nodes 1. Physical layer – Physical layer focuses on transmissions of data bits over communication lines 2. Data link layer – The data link layer concerns with the transfer of data over the communication links provided by physical layer. 3.
Network layer – Is concerned with the routing of data across the network from one end to another end. With this network layer converts the data into packet and makes sure that the packet is delivered to their specific final destination where the packet is again converted into data. 4. Transport layer – The main concern of the transport layer is to isolate the upper three layers from the network so that if there are any changes to the network equipment technology will be confined to lower three layers. 5. Session layer- The session layer provides a structured means for data exchange between user processes on communicating hosts. . Presentation layer – The presentation layer provides represents the application data communicated between two user processes. 7. Application layer – It is concerned about what the data means to application. It provides standards for support a variety of application independent services. CONCLUSION:- In conclusion communication network helps us provide all the information using internet protocols and through its different layers. It’s a network which is divided in wide area for receiving and transmitting information and data from computer to another.
Communication networks have their types depending on the area and how large the network is. With all the network division from region to region each have their own restriction through which the network are privately used or publically. Work cited Hekmat,Sharam. “CommunicationNetworks. “N. p. ,n. d. Web. Apr. 2013. <http://www. pragsoft. com/books/CommNetwork. pdf>. Patel, Mayur. “The Communications Network. ” The Communications Network RSS. The Communications Network, 26 Apr. 2013. Web. 29 Apr. 2013. <http://www. comnetwork. org/>. AG, SAMSON. “Communication Networks. ” SAMSON. N. p. , n. d. Web. <: http://www. samson. de>.