7. Consider the problem of recovering from host crashes (i.e., Fig. 6-18 of textbook; see below). If the interval between writing and sending an acknowledgement, or vice versa, can be made relatively small, what are the two best sender-receiver strategies, for minimizing the chance of a protocol failure? Explain why. Strategy used by receiving host Strategy used by sending host Always retransmit Never retransmit Retransmit in SO Retransmit in S1 First ACK, then write AC(W) AWC C(AW) OK OK DUP OK LOST LOST DUP LOST OK LOST OK OK OK DUP LOST Protocol loses a message First write, then ACK C(WA) OK LOST LOST OK = Protocol functions correctly Protocol generates a duplicate message WAC WC(A) DUP DUP OK OK OK DUP DUP OK

7. Consider the problem of recovering from host crashes (i.e., Fig. 6-18 of textbook; see below). If the interval between writing and sending an acknowledgement, or vice versa, can be made relatively small, what are the two best sender-receiver strategies, for minimizing the chance of a protocol failure? Explain why. Strategy used by receiving host Strategy used by sending host Always retransmit Never retransmit Retransmit in SO Retransmit in S1 First ACK, then write AC(W) AWC C(AW) OK OK DUP OK LOST LOST DUP LOST OK LOST OK OK OK DUP LOST Protocol loses a message First write, then ACK C(WA) OK LOST LOST OK = Protocol functions correctly Protocol generates a duplicate message WAC WC(A) DUP DUP OK OK OK DUP DUP OK

Principles of Information Security (MindTap Course List)

6th Edition

ISBN:9781337102063

Author:Michael E. Whitman, Herbert J. Mattord

Publisher:Michael E. Whitman, Herbert J. Mattord

Chapter6: Security Technology: Access Controls, Firewalls, And Vpns

Section: Chapter Questions

Problem 2RQ

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Similar questions

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