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CONE theory

### CONE Lab - Link - Numerical exercises

Problem 12 (Ch. 5 of Computer Networking by J.F. Kurose and K.W. Ross)
Consider three LANs interconnected by two routers, as shown in the diagram below.

a) Redraw the diagram to include adapters.
b) Assign IP addresses to all of the interfaces. For LAN 1 use addresses of the form 111.111.111.xxx ; for LAN 2 uses addresses of the form 122.222.222.xxx ; and for LAN 3 use addresses of the form 133.333.333.xxx .
d) Consider sending an IP datagram from host A to host F. Suppose all the ARP tables are up-to-date. Enumerate all the steps as done for the single-router example in section 5.3.2.
e) Repeat (d), now assuming that the ARP table in the sending host is empty (and the other tables are up-to-date).

Solution to problem 12

Problem 13 (Ch. 5of Computer Networking, 2nd ed. by J.F. Kurose and K.W. Ross)
Recall that with the CSMA/CD protocol, the adapter waits K*512 bit times after a collision, where K is drawn randomly. For K=100, how long does the adapter wait until returning to Step 2 for a 10 Mbps Ethernet? For a 100 Mbps Ethernet?

Solution to problem 13

Problem 14 (Ch. 5of Computer Networking, 2nd ed. by J.F. Kurose and K.W. Ross)
Suppose nodes A and B are on the same 10 Mbps Ethernet segment, and the propagation delay between the two nodes is 225 bit times. Suppose node A begins transmitting a frame, and before it finishes station B begins transmitting a frame. Can A finish transmitting before it detects that B has transmitted? Why or why not? If the answer is yes, then A incorrectly believes that its frame was successfully transmitted without a collision.
Hint: Suppose at time t=0 bit times, A begins transmitting a frame. In the worst case, A transmits a minimum size frame of 512+64 bit times. So A would finish transmitting the frame at t=512+64 bit times. Thus the answer is no if B's signal reaches A before bit time t=512+64 bits. In the worst case, when does B's signal reach A?

Solution to problem 14