All Networks

All Networks

1. A file server

   • A device which controls access to separately stored files, as part of a multi-user system.
     • Sharing devices such as printers saves money.
     • Security Problems- explicit programming required
     • data is easy to back up as it stored by a file server
     • No standardized control over structure of files

2. A client-network server

   • The clients run programs and access data that are stored on the server. Compare peer-to-peer network.
     • Centrelization: Access rights and resource allocation is done by Servers.
     • Proper Management : All the files are stored at the same place. In this way, management of files becomes easy. Also it becomes easier to find files.
     • Back-up and Recovery possible : As all the data is stored on server its easy to make a back-up of it. Also, in case of some break-down if data is lost, it can be recovered easily and efficiently. While in peer computing we have to take back-up at every workstation.
     • Changes can be made easily by just upgrading the server. Also new resources and systems can be added by making necessary changes in server.
     • Congestion in Network :Too many requests from the clients may lead to congestion, which rarely takes place in P2P network. Overload can lead to breaking-down of servers. In peer-to-peer, the total bandwidth of the network increases as the number of peers increase.
     • Client-Server architecture is not as robust as a P2P and if the server fails, the whole network goes down. Also, if you are downloading a file from server and it gets abandoned due to some error, download stops altogether. However, if there would have been peers, they would have provided the broken parts of file.
     • Cost : It is very expensive to install and manage this type of computing.
     • You need professional IT people to maintain the servers and other technical details of network.

3. Peer to peer network

   • Created when two or more PCs are connected and share resources without going through a separate server computer.
     • No need for a network operating system
     • Slows down the performance of the user if lots of poeple are using it
     • No need for an expencive server as indivdual work stations are used
     • files and folders can not be centerally backed up
     • without a logical filing system in can be hard to find where files have been stored.
     • If one comnputer fails it will not harn the rest of the server it just means the files are not available to that user at that moment in time.

4. Bus Network

   • A network topology in which nodes are connected in a daisy chain by a linear sequence of buses.
     • cheap to install, as it doesn’t require much cable
     • if the main cable fails or gets damaged the whole network will fail
     • easy to install
     • as more workstations are connected the performance of the network will become slower because of data collisions
     • every workstation on the network "sees" all of the data on the network – this is a security risk

5. Star Network

   • A data or communication network in which all nodes are independently connected to one central unit.
     • very reliable – if one cable or device fails then all the others will continue to work
     • expensive to install as this type of network uses the most cable (network cable is expensive)
     • high performing as no data collisions can occur
     • if a hub or switch fails all the devices connected to it will have no network connection

6. Ring network

   • Network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring.
     • This type of network can transfer data quickly, even if there are a large number of devices connected because the data only flows in one direction, so there won’t be any data collisions.
     • Network is highly dependent on the wire which connects different components.
     • If the main cable fails or any device is faulty then the whole network will fail.
     • Each computer has equal access to resources.

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