Efficiency versus Delay for a Sliding-Window Data-Link Control Protocol
This Demonstration gives the efficiency of a sliding-window data-link control protocol as a function of the delay between a sender and a receiver. The link rate, frame (or packet) size and window size (in frames) are adjustable parameters. This link is assumed to be error free.[more]
Data-link control protocols are used to ensure reliable and efficient data transmission in computer networks by managing the flow of data between a sender and a receiver. Sliding-window data-link control protocols operate in two regimes: the large and small window. The efficiency is 100% in the large-window regime and decreases as the delay increases in the small-window case. The threshold is a function of the delay, link rate, frame (or packet) size and window size (in frames). This Demonstration showcases the threshold effect and how it changes with the adjustable parameters.[less]
The following parameter definitions and relationships are used:
is the link rate (b/s),
is the effective transmission rate in bits/sec = ,
is the efficiency,
is the one-way delay (sec),
is the window size,
is the frame size (bits).
If , then (large-window case).
If , then (small-window case).
 A. Leon-Garcia and I. Widjaja, Communication Networks: Fundamental Concepts and Key Architectures, 2nd ed., Boston: McGraw Hill, 2004.
 A. Tanenbaum and D. J. Wetherall, Computer Networks, 5th ed., Boston: Pearson Prentice Hall, 2011.