A network engineer analyzes a packet capture of an active application stream during heavy network load. The capture reveals that the receiving host continuously updates the 16-bit Window field in its acknowledgment segments to smaller values, causing the sending host to reduce the amount of unacknowledged data sent before waiting for an ACK. Which statement correctly identifies this transport layer mechanism and its operational contrast with UDP?
- TCP employs dynamic windowing for receiver-driven flow control to prevent buffer overflow, whereas UDP lacks flow control mechanisms and a window size header field entirely.Cevap
- BTCP uses the window field to perform intermediate router rate limiting, whereas UDP relies on its 8-byte header to sequence packets and request retransmissions.
- CTCP windowing triggers automatic segment retransmission upon packet corruption, whereas UDP uses a variable 20-byte header to negotiate transmission window sizes.
- DTCP reduces the window size to signal Path MTU Discovery (PMTUD) updates, whereas UDP provides sequence tracking to manage buffer exhaustion without acknowledgments.
Cevap
TCP employs dynamic windowing for receiver-driven flow control to prevent buffer overflow, whereas UDP lacks flow control mechanisms and a window size header field entirely.
The correct answer accurately describes TCP flow control. The TCP header includes a 16-bit Window field that allows the receiving host to advertise its available buffer space. As the buffer fills, the receiver reduces the window size, instructing the sender to transmit less data before awaiting an ACK. In contrast, UDP has a simple, fixed 8-byte header (Source Port, Destination Port, Length, Checksum) and does not provide flow control, windowing, or rate management.
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TCP Sliding Window Flow Control vs. UDP Stateless Header Overhead
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