At Event B, the following actions will take place ACK0 received, pk4 sent, sende

Question

At Event B, the following actions will take place

ACK0 received, pk4 sent, sender window doesn't move

ACK0 received, pk4 sent, sender window moves to start at 1

ACK0 received, pk2 resent

ACK0 received, pk1, pk2 and pk3 resent

A)

ACK0 received, pk4 sent, sender window doesn't move

B)

ACK0 received, pk4 sent, sender window moves to start at 1

C)

ACK0 received, pk2 resent

D)

ACK0 received, pk1, pk2 and pk3 resent

Host A Host B pkt0 sent 01234567 pktl sent 1 2 3 4 5 6 789 pkt0 rcvd, delivered, ACKO sent :01 2 3 4567 pkt2 sent 01 23 456789 pkt1 revd, delivered, ACK1 sent :0123 456789 (loss) pkt3 sent, window full: 01234567 8 9 : Event A Event B : Event C Event F Event D pkt2 TIMEOUT : Event E

Explanation / Answer

Since the timeout hadn't happended at event B , sender won't resend any packet. Hence, options 3 and 4 are incorrect.

At Event B, sender receives the acknowledgment of packet-0, i.e ACK0 and it transmits packet-4. But the receiver understands that it is out of order packet and discards it. Since the sender sent the packet-4, it's window moves to start at 1.

Hence, Option-B is the correct answer.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.