For each of the following scenarios, state in the corresponding entry in the table below whether it is permitted or not by that mode of multicast.

Question

Suppose the following events take place in chronological order, in a multicast group participated by three processes P1, P2, and P3:
P1 multicasts m1.
P2 responds to m1 by multicasting m2.
P3 multicasts m3 spontaneously.
P1 responds to m3 by multicasting m4.
P3 responds to m2 by multicasting m5.
P2 multicasts m6 spontaneously.

a. All processes are delivered m1, m2, m3, m4, m5, m6, in that order
b. P1 and P2 are each delivered m1, m2, m3, m4, m5, m6.
P3 is delivered m2, m3, m1, m4, m5, m6.
c. P1 is delivered m1, m2, m5, m3, m4, m6
P2 is delivered m1, m3, m5, m4, m2, m6
P3 is delivered m3, m1, m4, m2, m5, m6
d. P1 is delivered m1, m2, m3, m4, m5, m6
P2 is delivered m1, m4, m2, m3, m6, m5
P3 is delivered m1, m3, m6, m4, m2, m5.
e. P1 is delivered m1, m2, m3, m4, m5, m6
P2 is delivered m1, m3, m2, m5, m4, m6
P3 is delivered m1, m2, m6, m5, m3, m4.
f. P1 is delivered m2, m1, m6
P2 is delivered m1, m2, m6
P3 is delivered m6, m2, m1
g. No message is delivered to any of the processes

Answer 1

Note that the following relations exist among the messages:
Causality: m1->m2->m5 m3 - > m4
FIFO: m1->m4 (based on P1), m2->m6(based on P2), m3->m5(based on P3)