Hello I am trying to understand the GBN protocol and I encountered the following question during my homework.
Assume that we have GBN protocol with a window size of 20. The sender sends 15 packets one after the other with seq numbers from 1-15. After that, the sender is waiting to get acks from the server (the sender doesn't have any more info yet).
Now Firstly ack #3 arrives then ack #7 arrives and then ack #11 arrives. after that, we get a TIME-OUT.
the question is: in response to that T.O mentioned above the the sender will send ----- packets
As I understand after we get the 11th ack we know that everything before has been working just fine.
But I'm getting confused with the window size and the sequence number of the messages.
Please anyone can explain and help.