Assuming that all routers and hosts are working properly and that all software in both is free of all errors, is there any chance, however small, that a packet will be delivered to the wrong destination

Consider the GBN protocol with a sender window size of 4 and a sequence number range of 1,024. Suppose that at time t, the next in-order packet that the receiver is expecting has a sequence number of k. Assume that the medium does not reorder messages. Answer the following questions: a. What are the possible sets of sequence numbers inside the sender's window at time !? Justify your answer. b. What are all possible values of the ACK field in all possible messages currently propagating back to the sender at time? Justify your answer.

For each of following ICMP messages, list their possible senders (routers, non-destination hosts, and destination hosts). a) Type: destination unreachable,Code: 2/3 – protocol/port is unreachable b) Type: source quench,Code: 0 c) Type: time exceeded,Code: 1 (note when the final destination does not receive all of the fragments in a settime, it discards the received fragments and sends a time-exceeded message (code 1) tothe original source) d) Type: Redirection,Code: 1 – redirect to a host-specific route

UDP and TCP use 1s complement for their checksums. Suppose the receive received two 3-bits payload messages: 010, 001. The checksum received is 100. Find all possible original messages. How many errors were made during the transmission?