CS 558 - Computer Networking
Homework 9

• Question 1 (30 pts)

• High light the links of the forward (path) tree that is rooted at node A in the following network: (20 pts)

• Give the content of the routing table for node A:

• Question 2 (20 pts)

• High light the links of the reverse (path) tree rooted at node A in the following network:

• Suppose the multicast uses DVMRP to send multicast messages and currently only nodes D and E are serving multicast members of some multicast group.

High light the links the multicast tree that is rooted at node A that DVMRP will use in transmitting multicast messages:

• Question 3 (25 pts)

• Can pyramid broadcast be used in live video transmission ? If yes, explain why, if no, explain why not. (5 pts)

• Suppose the video data consumption rate is 1 Mbps. We use pyramid broadcast to transmit 100 video objects and each video object is 100 min in length. The total bandwidth of the transmissin medium is 1 Gbps.

1. If we divide the video objects into 4 fragments, what is the maximum size ratio f between the successive fragments so that the receiver will not be disrupted (5 pts) ?

2. And if we divide the video objects into 10 fragments, what is the maximum size ratio between the successive fragments so that the receiver will not be disrupted (5 pts) ?

• Question 4 (25 pts)

Suppose the video data consumption rate is 1 Mbps. We want to broadcast 100 video objects and each video object is 100 min in length. The total bandwidth of the transmissin medium is 1 Gbps.

• What is the access time if we use the staggered broadcast method ? (5 pts)

• Suppose we use the pyramid broadcast method and divide the video objects into 4 fragments. What is the access time ? (10 pts)

• We use the pyramid broadcast method and divide the video objects into 10 fragments. What is the access time ? (10 pts)