Why a strict NAK-only strategy would leave the sender unsure about whether any packets got through ? Is there any solution about this?

Question

The NAK-based strategy is that it can send NAK message from the receiver indicating that particular data was not received . And I want to know why NAK-based strategy would leave the sender unsure about whether any packets got through ? Is there any solution about this ?

Answer 1

The sender is unsure whether anything got through because it has no idea whether it can hear the receiver's NAKs. A 100% successful transmission looks exactly the same as a transmission with cut cables; the sender hears only silence.

Solutions? Well, you could use ACKs. I'm not very familiar with protocol design, so I'm not sure what better solutions are available or how to optimize this.