Computer Networks

The transport layer is responsible for end-to-end communication between devices in a network.
TCP (Transmission Control Protocol) provides reliable, connection-oriented communication.
It performs the following key functions:
- Ensures packet delivery in order
- Performs error detection and retransmission
- Maintains flow control and congestion control
While IP operates at the network layer and handles addressing and routing, it does not ensure packet order.
UDP is also in the transport layer but does not guarantee order or reliability.
HTTP is an application layer protocol built over TCP.
Thus, TCP is the correct protocol that ensures delivery in the correct sequence at the transport layer.