CECS 474 Computer Network Interoperability
Assignment 3
Due Monday, February 16, 2009
Given the following information about a network:
A two-hop network between source A and destination B.
The transmission links are both T1 lines with bandwidth 1.544 Mbps*.
Propagation delay across the line is 2.0 * 108 meters/sec.
We wish to send a 50 Mbit* message from source A to destination B.
I. How long does it take for the message to reach destination B if circuit switching is
used?
You may assume:
the call set-up/confirmation/teardown messages are all 100 Bytes long.
the processing delay for set-up/confirmation/teardown messages (at all
nodes A, B and C) is 0.1 second.
II. How long does it take for the message to reach destination B if packet switching is
used?
You may assume:
the overhead for each packet (header and trailer) is 512 bits.
the maximum packet payload size is 10,000 Bytes (the header/trailer is
added to this).
the store-and-forward processing delay at each node is 0.001 seconds.
no errors occur during transmission.
Dr. Tracy Bradley Maples (Spring 2009)
Source A Destination B
2000
kilometers
4000 kilometers
Node C
