Network - Data unit
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About
A buffer in Networking is called a data unit.
When data is sent across a network, it is sent as thousands of small chunks called data unit, so that many different users can download the same data at the same time. If the requested data were sent as single big chunks, only one user could download one at a time, which obviously would make the application (such as the Web) very inefficient and not much fun to use.
In the OSI model of computer networking, a data unit has different terminology.
| Layer | Data Unit Name |
|---|---|
| layer 2 - the data link layer | frame (ethernet) |
| layer 3 - the network layer | packet (IP) |
| layer 4 - the transport layer | segment (TCP) or datagram (UDP) |
For a TCP/IP communication over Ethernet,
- a TCP segment is carried in
- one or more IP packets,
- which are each carried in one or more Ethernet frames.