Which protocol is the main transport protocol in the internet suite, giving reliable, connection-oriented communication?

The Transmission Control Protocol (TCP) is indeed the primary transport protocol in the Internet suite that provides reliable, connection-oriented communication. TCP establishes a connection between the sender and receiver before data is transmitted, allowing for the orderly and error-checked transfer of data.

This connection-oriented nature means that TCP ensures data packets are delivered in the correct sequence, and it incorporates mechanisms for flow control and congestion management. It also includes acknowledgments for received packets, enabling the detection and retransmission of any lost or corrupted packets. These features make TCP suitable for applications where data integrity and order are critical, such as web browsing, file transfers, and email.

In contrast, other protocols mentioned serve different roles. For example, the User Datagram Protocol (UDP) is a connectionless protocol that prioritizes speed over reliability and does not guarantee packet ordering. The Session Initiation Protocol (SIP) is used for setting up and controlling communication sessions, often in voice over IP (VoIP) contexts, but it does not handle the actual data transport itself. The Internet Control Message Protocol (ICMP) is mainly used for diagnostic and control purposes, such as error reporting and network status inquiries, rather than for transporting application data.