Networks

Networks

1. Advantages

   • Log on any computer
     • Files available on every computer
   • Print, internet,email on same computer.

2. DIsadvantages

   • Expensive
   • More room for error
   • Difficult to set up
     • Malware

3. LAN

   • Local Area Network

4. WAN

   • Wide Area Network

5. Bus Topology

   • A single cable that runs through the network
   • Advantages
     • Cheap to install (only one wire needed)
   • Disadvantages
     • High chance of catastrophic failure (a break in the central cable takes out the entire network)
       • High chance of collisions (multiple communications on the same cable that corrupt each other, slowing down the network)
         • More computers mean more collisions, so the network gets slower as it gets bigger
       • The Internet
         • The Internet is a huge, global inter-connected network of devices.
           • When we join the Internet, we use a broadband router to connect to one of the existing nodes.
             • While a mesh network like the Internet is very reliable, it has a big downside when compared to other topologies like a star
           • It is impossible to break the Internet, since another route can always be found
             • There are multiple different routes between any two nodes
             • The Internet is a giant mesh of computers
         • Before we can transmit, we need to decide what route the data is going to take
           • In order to do this, each node continually tests its connections and assigns them a “cost” – a lower cost means faster connection.
             • Route-finding algorithms are used to determine which route through the mesh will have the lowest cost, and therefore take least time
               • Data is split into small chunks called packets. Each packet is sent along the lowest cost route. The packets are re-assembled on the other side.

6. Star Topology

   • The computers are connected to a central switch
   • Advantages
     • Fast
       • Easy to add new computers
     • Low chance of failure
   • Disadvantages
     • Expensive
       • Failure of the switch will take down the network

7. Ring Topology

   • Computers are connected to each other in ring.
   • Advantages
     • Cheap to install (one cable per computer)
       • No collisions - only one computer is transmitting on each cable
   • Disadvantages
     • High chance of catastrophic failure (if any cable breaks or any computer goes down, the entire network fails
       • Difficult to add new computers

8. Mesh Topology

   • Mesh topology is a type of networking where all nodes cooperate to distribute data amongst each other.
   • Advantages
     • Manages high amounts of traffic, because multiple devices can transmit data simultaneously. A failure of one device does not cause a break in the network or transmission of data. Adding additional devices does not disrupt data transmission between other devices.
     • The cost to implement is higher than other network topologies, making it a less desirable option. Building and maintaining the topology is difficult and time consuming. The chance of redundant connections is high, which adds to the high costs and potential for reduced efficiency.
       • Rather than using a star, bus or ring topology, each node is connected to one or more other nodes in an ad-hoc manner The layout of these nodes is called a Mesh Topology In a mesh topology, there is excellent resilience to outages as messages can take many different routes to reach a destination If any node or connection becomes unavailable, the message can simply take a different route

9. IP Adress

   • Internal
     • When communicating inside the building
   • External
     • When communicating outside they building
   • IP Address must be unique so that the file gets sent to the correct computer.

Bilder und Dateien der Mindmap