Karn's algorithm addresses the problem of getting accurate estimates of the round-trip time for messages when using the Transmission Control Protocol (TCP) in computer networking.
[2] Accurate round trip estimates in TCP can be difficult to calculate because of an ambiguity created by retransmitted segments.
Karn's Algorithm ignores retransmitted segments when updating the round-trip time estimate.
This algorithm has proven to be extremely effective in balancing performance and efficiency in networks with high packet loss.
Networks that have high round-trip time and retransmission timeouts should be investigated using root cause analysis techniques.