Need HELP: Sliding window, Selective Repeat

[dave159]

Hi. i'm very confused about this topic.
for example:
1. sliding window(3)
HOST A send 5 packets to host B: 1,2,3,4,5. host B didn't receive packet 3,4.
so host B send ACK 1, ACK 2 ,and then what host B\A send??

2. the same example but now with selective repeat..
please help me
thanks

 

[donadoni]

host b accepted the packet 1-2 and 5 and sent an ACKnowledgement to let host a know they were recieved.


no ack was sent for 34 so host a will re-send the packets after realising no ACK has been sent from B