Higher bandwidth–delay products require larger window sizes (GBN/SR) to maintain high throughput. 5. Hybrid ARQ (HARQ)
) before needing an ACK. If a frame is lost, the receiver discards all subsequent frames, and the sender must retransmit all frames starting from the lost one. Better utilization than Stop-and-Wait. Cons: High retransmission overhead in poor channels. 3.3. Selective Repeat ARQ (SR) the receiver discards all subsequent frames
The receiver sends an ACK to confirm the successful receipt of a packet. the receiver discards all subsequent frames