3.4 Summary of Session 3
In this session you’ve looked at how switches use MAC addresses to deliver data across a local area network.
You’ve also looked at the hierarchical layers used in communication networks and how different processes – in this case switching and routing – happen at different layers. You have also met the terms ‘segmentation’ and ‘encapsulation’, which describe how data is split up into data units, and control information added, so that the data units can be sent across a network and delivered to their destination device.
New terms
In this session you have met the following terms.
broadcast |
To send a message to all devices on a network. |
broadcast domain |
The set of devices on a network that will be sent the same broadcast messages. |
data unit |
A small chunk of data, of a certain size and format. |
encapsulation |
The process of each layer adding its own information and creating its own data unit. |
forwarding table |
Table used by a switch to associate MAC addresses of devices with port numbers to enable frames to be forwarded to their destination. |
frame |
A data unit at the Network Access layer. |
Internet layer |
Layer of the TCP/IP protocol suite with responsibility for getting data across networks. |
Network Access layer |
Bottom layer of the TCP/IP protocol suite with responsibility for delivering data within the local area network. |
packet |
A data unit at the Network Access layer. |
payload |
The part of a data unit that is the actual user data. |
port |
In this context, the physical sockets into which network cables are plugged. |
router |
A network device responsible for getting data across networks. |
segmentation |
The process of breaking data down into smaller units of the same size. |
switch |
A network device responsible for delivering data within the local area network. |