LANs: Introduction & Ethernet 1. Discuss factors that limit speed of operation and range in cables. 2. Discuss the techniques used to enable Ethernet to operate at speeds of 100 Mbps, or more. 3. Consider the transfer of a million bytes of data from one station to another, distance D apart, by means of encapsulation.
What is the total elapsed time and effective throughput for the following cases: a. A circuit-switched, star topology local network. Call set-up time is negligible and the data rate is 64 kbps. b. An Ethernet network transmitting data at a rate of 10 Mbps. The propagation speed is 200 m / ms .
c. An Ethernet network transmitting data at a rate of 100 Mbps. The propagation speed is 200 m / ms . Where D is: D (m) ANSWERS a. b.
c. 200 200 500 4. The maximum throughput S for a CSMA/CD LAN is given by: Where S is normalised and k is the ratio of the medium propagation time to the time taken for one station to transmit all of the bits of one frame onto the bus. An Ethernet network has a maximum end-to-end length of 200 m and operates at a transmission speed of 100 Mbps.
Assuming a frame length of 1526 bytes, determine the value of k and hence maximum throughput S. Assume velocity of propagation of signals is 200, 000 km / s . 5. Draw a flowchart to illustrate the CSMA/CD protocol used by Ethernet.
6. Explain why an Ethernet network may be idle, even though some stations have frames to transmit. 7. Discuss why Ethernet MAC protocol is not inherently suitable for video communication. Under what circumstances might video operation be supported? 8. With reference to the CSMA/CD medium access technique, explain the main cause of collisions and clearly indicate what is meant by the terms vulnerable time and collision window.
The Essay on Fast Ethernet 100 Network Gigabit
The urging demand for higher transmission speeds prompted by fast network growth has been answered by the creation Fast Ethernet specification (IEEE 802. 3 u) known as 100 BASET. Fast Ethernet has put the plank for data transmission rate from 10 Megabits per second to 100 Megabits, but most importantly it was possible to achieve with only minimal changes to the existing cable structure. Moreover, ...
9. Calculate the slot time in a UTP based network. Assume that segment length is 100 m max. and hubs are ideal.
10. Sketch the MAC frame structure used by the IEEE 802. 3 CSMA/CD LAN standard. Clearly explain the purpose of each field contained within the frame 11.
Explain why the CRC check field is not applied to the preamble of the IEEE 802. 3 frame. 12. Define the term ‘collision domain’.
13. Determine the maximum slot time for an Ethernet 10 Base 2 network containing 5 segments. Compare slot time with the duration of a MAC frame of minimum length. Ignore preamble and SFD fields. 14. Repeat the question above for the case of a Gigabit Ethernet network, again for minimum frame length.
15. What is the minimum length of a standard Ethernet frame? Explain why such a constraint is necessary?
