A network engineer is troubleshooting performance degradation in a real-time voice and video collaboration tool deployed across an enterprise WAN link with a 2% packet loss rate. Testing shows that when using TCP for streaming media, audio output suffers from severe stuttering and growing latency spikes. Switching the stream to UDP resolves the latency spikes, allowing minor packet loss without blocking the media pipeline. Which characteristic of connection-oriented protocols causes the severe latency spikes observed during packet loss under TCP?
- TCP relies on cumulative acknowledgments and in-order byte streaming, causing head-of-line blocking in the receiver buffer while waiting for missing segment retransmissions.Answer
- BTCP operates at Layer 3 of the OSI model, forcing every intermediate router to perform connection handshake renegotiations upon packet loss.
- CUDP provides dynamic windowing and flow control mechanisms that automatically drop delayed frames at the sender to maintain real-time synchronization.
- DUDP uses a 20-byte header containing mandatory SYN/ACK flags that reduce per-packet payload overhead compared to TCP's 8-byte header structure.
Answer
TCP's reliance on cumulative acknowledgments and in-order byte streaming causes head-of-line blocking, forcing the receiver buffer to delay processing subsequent packets until missing segments are retransmitted.
TCP is a connection-oriented protocol that guarantees delivery and strict ordering. When packet loss occurs on a network link, TCP's receiver buffer experiences head-of-line blocking, where correctly received subsequent packets cannot be passed to the application until the missing segment is retransmitted and acknowledged. In real-time voice and video streams, this delay causes severe latency spikes and stuttering.
Step-by-Step Solution
Key Concept
Connection-Oriented vs Connectionless Transport Behavior
Estimated Time:1m 30s