Home » Cisco » 300-101 » Which TCP feature ensures steady state throughput?
A network engineer wants to ensure an optimal end-to-end delay bandwidth product. The delay is less than 64 KB. Which TCP feature ensures steady state throughput?
A. Window scaling
B. Network buffers
C. Round-trip timers
D. TCP acknowledgments
Correct Answer: A
Explanation/Reference:
options can be carried in a TCP header. Those relevant to TCP performance include
Window-scale option : This option is intended to address the issue of the maximum window size in the face of paths that exhibit a high-delay bandwidth product. This option allows the window size advertisement to be right-shifted by the amount specified (in binary arithmetic, a right-shift corresponds to a multiplication by 2). Without this option, the maximum window size that can be advertised is 65,535 bytes (the maximum value obtainable in a 16-bit field).
The limit of TCP transfer speed is effectively one window size in transit between the sender and the receiver. For high-speed, long-delay networks, this performance limitation is a significant factor, because it limits the transfer rate to at most 65,535 bytes per round-trip interval, regardless of available network capacity. Use of the window-scale option allows the TCP sender to effectively adapt to high-band-width, high-delay network paths, by allowing more data to be held in flight. The maximum window size with this option
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