Typical contents of a packet

Two different types of data:

1. Control information
   • Source and destination addresses
   • Order number of packet
   • Control signals
   • Error control bits
2. The actual data

Network collisions

<aside> ♻️ Occurs when two transmissions attempt to use the same connection medium at the same time

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How they are dealt with…

1. Collision itself generates a frequency that can be detected by all connected devices
2. The two collided devices detect this frequency and are alerted that their transmissions failed
3. They each wait a randomly generated length of time before reattempting the transmission
4. If another collision occurs, the process repeats with more random timeframes

Routing

<aside> 👉 Determines the path each data packet takes and ensures that packets are delivered to their destination as quickly as possible

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Bandwidth - a measure of how much data can be fitted onto a cable at any point

High bit rate is required when a large amount of data needs to be sent in a short period of time (e.g. video conferencing)

Static routing

<aside> ↩️ Each router has access to a table that tells it which path to forward data, based on its destination address. Simple to implement, but not suitable for networks that change often, or frequently have new devices added

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Dynamic routing

<aside> ↩️ Routers learn the locations of other devices based on monitoring source and destination addresses of data that is forwarded Changes to the network are automatically identified by the router

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