>"A basic assumption of TCP is that retransmission only happens due to congestion." This is a not a basic assumption of TCP. TCP's inability to differentiate b

>"A basic assumption of TCP is that retransmission only happens due to congestion." This is a not a basic assumption of TCP. TCP's inability to differentiate between problems due to congestion vs problems due to noisy or lossy channels is based on the assumption that the link-layer protocol operates independently of higher-layer protocols IP, TCP, etc.