Section 16.5. Exercises

16.5. Exercises

1.	Label routing in MPLS networks is similar to VPN tunneling. Compare these two schemes in terms of Traffic engineering capability Security
2.	Traffic engineering in MPLS networks can be done in the following two locations. Compare the advantages of each approach. Egress nodes estimate routing to and from all ingress nodes. A preassigned router estimates routing and propagates to all LSRs.
3.	Consider the MPLS network shown in Figure 16.10; suppose that we want to use traffic engineering. Assume that the table of egress router R4 contains 26 (In Label), (Out Label), D (dest.), and 0 (Output Port). We want to route packets received at the ingress router R7 to egress router R4 through R1-R2-R5-R4. Show the MPLS routing table for R1. Show the MPLS routing table for R3.
4.	Consider an overlay network that consists of five connected nodes. Compare two methods for a peer-to-peer connection on top of the Internet, using A ring topology A star topology
5.	Suppose that two peers are connected to a four-node overlay network interconnected with a ring topology, as shown in Figure 16.11. There are 200 requests per second arriving at one of the peers, and the average service rate is 230 requests per second. Assuming that the time required to establish a connection is 10 ms, that the time to finish the service as soon as the connection establishes is 120 ms, and that there is an equal chance that the peer is connected or not connected: Find the average service time of the peer. Find the total utilization of the peer.
6.	Computer simulation project . Carry the computer program you developed for the simulation of the seven-node network in Chapter 7 and add a subprogram to simulate the operation of overlay networks. To do this, use the computer program, and construct the seven-router network shown in Figure 16.11. Simulate a packet transfer through the original network from R 1 to R 4 . Compare the results of part (a) to the case, using the overlay network shown in the figure.