27-08-2014, 02:24 PM
Project work is major part of course. It is a period in which we are introduction the actual process of making a project successful. In other words, we can say that project lab course training is provided for the familiarization with the environment in which the development of an actual project is done. In the department of Computer Science and Engineering, I am introduced the process of networking engineering, which is I owe and includes not only the process but actual process of Software development. During the period of degree in Computer Science and Engineering, I have studied all the theoretical subjects, which are required for the development of Network or some other design. But this is the time When I put my knowledge to actual work and learn how to combine all the aspects of Network engineering. The objectives of doing project work is to raise the level of performance in one or more of its aspects and this may be achieved by careful learning of group relation, coordination and cooperation provides an overview of the total development
Introduction to Networking
Networking is a practice of linking of two or more computing devices such as PCs, printers, faxes etc., with each other. Connection between two devices is through physical media or logical media to share information, data and resources. Networks are made with the hardware and software.
Cable/media
Computer network
There are many different ways to connect your computer to another computer or a network. Using Windows2000, you can connect your computer to:
Another computer using a direct cable connection. A private network using a modem or an integrated service digital network (ISDN) adapter or a network adopter card. A network using a virtual private network (VPN) connection. Another computer by having another computer call your computer.
The interconnected collection of autonomous computers is called computer network. Two computers are said to be interconnected if they are able to exchange information. The connection need not be via a copper wire; fiber optics, microwaves and communication satellites can be used.
Computer networking is the scientific and engineering discipline concerned with communication between computer systems. Such networks involve at least two devices capable of being networked with at least one usually being a computer.
ii) Types of Networking
· Wired network
· Wireless network
Wired networks:
Wired networks are almost always faster and less expensive than wireless networks. Once connected, there is little that can disrupt a good-wired connection. Wired networks come in many forms, but the most popular are HomePNA and Ethernet. HomePNA uses the existing phone line wires in your home and Ethernet needs special network cabling.
Wireless Networks:
Mobile computers, such as notebook computers and personal digital assistants (PDAs) are the fastest- growing segment of the computer industry. Many of the owner of these computers have desktop machines on LANs and WANs back at the office and want to be connected to their home base even when away from home or en route. Since having a wired connection is impossible in cars and airplanes, there is a lot of interest in wireless networks.
Models of networking
Model means the connectivity of two computers. We have many types of networking models.
(i) Client – Server Model
(ii) Peer to Peer Model (Workgroup Model)
(iii) Domain Model
(i) Client –Server Model
In a Client server model we have one server and many clients. A Client can share the resources of server, but a server cannot share the resources on clients.
On the point of view of administrator it.s very easy to control the network because we combine with the server also at security point of view. It is very useful because it uses user level security in which users have to remember only one password to share the resources.
(ii) Peer to Peer Model (Workgroup Model)
In Peer to Peer networking model all computers are in equal status, that is we cannot manage centralization, administration security. In Peer to Peer networking client use operating system like Window 98, Window XP, Window 2000, Window Vista.
(iii) Domain Model
It is a mixture of client server and peer-to-peer model. In this clients can share their resources as peer-to-peer but with the permission of the server as in client server model therefore it is commonly used model because in this security is more as we can put restriction on both server and clients.
iii. Categories of Network
Local Area Network (LAN)
LAN is a computer network that is used to connect computers and work station to share data and resources such as printers or faxes. LAN is restricted to a small area such as home, office or college. Devices used in LAN are : HUB and switch. Media for LAN is UTP cables.
Campus Area Network (CAN)
Campus Area Network is a computer network made up of two or more LANs
Within a limited area. It can cover many buildings in an area. The main feature of CAN is that all of the computers which are connected together have some relationship to each other e.g. different buildings in a campus can be connected using different CAN. It will help to interconnect academic departments, library and computer laboratories. CAN is larger than LAN but smaller than WAN. Devices used in CAN are: HUB, Switch, Layer-3 switch, Access Point .And the media used for CAN is unshielded twisted pair of cables and Fiber Optics Cable.
Metropolitan Area Network (MAN)
MAN is the interconnection of networks in a city. MAN is not owned by a single organization. It acts as a high speed network to allow sharing resources with in a city. MAN can also be formed by connecting remote LANs through telephone lines or radio links. MAN supports data and voice transmission. The best example of MAN is cable T.V network in a city.
Wide Area Network (WAN)
WAN covers a wide geographical area which includes multiple computers or LANs. It connects computer networks through public networks like, telephone system, microwave, satellite link or leased line.
Most of the WANs use leased lines for internet access as they provide faster data transfer. WAN helps an organization to establish network between all its departments and offices located in the same or different cities. It also enables communication between the organization and rest world. Devices used in WAN is only Router.
3.NETWORKING COMPONENT
i) Routers:
A router
Routers are networking devices that forward data packets between networks using headers and forwarding tables to determine the best path to forward the packets. Routers work at the network layer of the TCP/IP model or layer 3 of the OSI model. Routers also provide interconnectivity between like and unlike media . This is accomplished by examining the Header of a data packet, and making a decision on the next hop to which it should be sent. They use preconfigured static routes, status of their hardware interfaces, and routing protocols to select the best route between any two subnets. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP.s network. Some DSL and cable modems, for home (and even office) use, have been integrated with routers to allow multiple home/office computers to access the Internet through the same connection. Many of these new devices also consist of wireless access points (waps) or wireless routers to allow for IEEE 802b/g wireless enabled devices to connect to the network without the need for a cabled connection.
• Provide filtering and network traffic control on LANs and WANs
• Can connect multiple segments and multiple networks
• Networks connected by routers are called internet works because they create a larger network of interconnected, smaller networks.
• When a router is introduced into a network, it creates more networks
• Routers create collision domains and they also create broadcast domains because a router will not pass broadcast traffic
– A broadcast domain is a group of network devices that will receive LAN broadcast traffic from each other
• Sub network
– Portion of the network created by manipulating a network address and breaking it down into smaller parts
• IP address
– 32-bit binary address used on TCP/IP networks
– Consists of a host portion and a network portion
ii) Switches:
A Linksys 48 Port Switch
A switch is a device that performs switching. Specifically, it forwards and filters OSI layer 2 datagrams (chunk of data communication) between ports (connected cables) based on the Mac-Addresses in the packets. This is distinct from a hub in that it only forwards the datagrams to the ports involved in the communications rather than all ports connected. Strictly speaking, a switch is not capable of routing traffic based on IP address (layer 3) which is necessary for communicating between network segments or within a large or complex LAN. Some switches are capable of routing based on IP addresses but are still called switches as a marketing term. A switch normally has numerous ports with the intention that most or the entire network be connected directly to a switch, or another switch that is in turn connected to a switch.
"Switches" is a marketing term that encompasses routers and bridges, as well as devices that may distribute traffic on load or by application content (e.g., a Web URL identifier). Switches may operate at one or more OSI layers, including physical, data link, network, or transport (i.e., end-to-end). A device that operates simultaneously at more than one of these layers is called a multilayer switch.
Switches are the core devices in today.s modern LANs. Switches are Layer 2 devices, like bridges. Switches keep tables of MAC addresses. Switches keep track of and examine Layer 2, Data Link addresses (MAC addresses) – more later. Switches learn about devices on each port and “decide” whether or not it needs to forward the traffic: Flood or Filter.
Switches look a lot like hubs, but internally are much different. Switches can learn where devices are on the network, so they do not have flood information (frames), but can FILTER them so the information only goes out the port towards the destination device.
iii) Network bridge:
A network bridge connects multiple network segments at the data link layer (layer 2) of the OSI model, and the term layer 2 switch is often used interchangeably with bridge. Bridges are similar to repeaters or network hubs, devices that connect network segments at the physical layer, however a bridge works by using bridging where traffic from one network is managed rather than simply rebroadcast to adjacent network segments. In Ethernet networks, the term "bridge" formally means a device that behaves according to the IEEE 802.1D standard—this is most often referred to as a network switch in marketing literature.
Since bridging takes place at the data link layer of the OSI model, a bridge processes the information from each frame of data it receives. In an Ethernet frame, this provides the MAC address of the frame.s source and destination. Bridges use two methods to resolve the network segment that a MAC address belongs to.
v Transparent bridging – This method uses a forwarding database to send frames across network segments.
v Source route bridging – With source route bridging two frame types are used in order to find the route to the destination network segment.
Bridges come in three basic types:
Ø Local bridges: Directly connect local area networks (LANs)
Ø Remote bridges: Can be used to create a wide area network (WAN) link between LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced by routers.
Ø Wireless bridges: Can be used to join LANs or connect remote stations to LANs.
(iv) Network topologies:
In networking, the term topology refers to the layout of the connected devices on a network. This article introduces the standard topologies of the computer networking. One can think topology as a network.s “shape”. This shape does not necessarily correspond to the actual physical layout of the device on the network.