TCP or UDP: Which One Behaves Like This?

About this interactive

From the lesson: - **TCP, built for reliability.** It establishes a connection before data moves, sequences the data so the far end can reassemble it in order, uses acknowledgments to find missing or bad data and resend it, and controls the flow so a receiver is not swamped. Its header is larger to carry all of that. - **UDP, built for speed.** It is connectionless: it just sends. It does not sequence, acknowledge or resend, and its header is small. If an application needs ordering or resends over UDP, the application does that work itself. Both protocols break data into pieces and use port numbers to reach the right service.

What you'll learn

Tell TCP from UDP by how each one behaves: connection setup, acknowledgments, resending lost data, sequencing and flow control
Recognize that UDP leaves reliability and ordering to the application above it

Aligned to

CompTIA Network+

1.1 Explain concepts related to the Open Systems Interconnection (OSI) reference model.

1.4 Explain common networking ports, protocols, services, and traffic types.

Cisco CCNA

1.5 Compare TCP to UDP

Key terms

Transmission Control Protocol: A connection-oriented transport protocol that ensures reliable, ordered, and error-checked delivery of data.
User Datagram Protocol: A connectionless transport protocol that sends data without establishing a connection or guaranteeing delivery.
Transport Layer: Layer 4 of the OSI model, responsible for end-to-end communication, flow control, and error recovery.
Retransmission: The process by which TCP resends segments when the receiver detects missing data based on expected sequence numbers.
Sequence Number: A 32-bit field in the TCP header that identifies the byte position of the first byte of data in a segment, allowing the receiver to reorder segments that arrive out of sequence and detect missing data. The receiving side uses the sequence number to send an acknowledgment confirming which byte it expects next.

Topics

Tcp Udp Transport Layer Reliability Interactive Streak Sort

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