State any four services provided by the transport layer of the OSI model. (4 marks)June/July 2020

The transport layer of the OSI (Open Systems Interconnection) model is responsible for providing end-to-end communication services to the upper layers of the model. It performs several key functions, including:

1. Segmentation and reassembly: The transport layer divides the data received from the upper layers into smaller units called segments, and reassembles the segments into the original data at the receiving end. This allows the data to be transmitted more efficiently over the network.
2. Flow control: The transport layer uses flow control techniques to ensure that the sender does not transmit data faster than the receiver can process it. This helps to prevent data loss and ensures that the transmission is efficient.
3. Error correction: The transport layer includes error detection and correction mechanisms to ensure that the data is transmitted accurately and reliably.
4. Multiplexing: The transport layer allows multiple logical channels to be multiplexed onto a single physical channel, which allows multiple applications to share the same network resources.
5. Congestion control: The transport layer monitors the amount of traffic on the network and adjusts the transmission rate to prevent network congestion. This helps to ensure that the network is used efficiently and that the performance of the system is not degraded.