* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download NetworkingReview
Piggybacking (Internet access) wikipedia , lookup
Multiprotocol Label Switching wikipedia , lookup
Distributed firewall wikipedia , lookup
Asynchronous Transfer Mode wikipedia , lookup
TCP congestion control wikipedia , lookup
IEEE 802.1aq wikipedia , lookup
Serial digital interface wikipedia , lookup
Computer network wikipedia , lookup
Network tap wikipedia , lookup
List of wireless community networks by region wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Airborne Networking wikipedia , lookup
Deep packet inspection wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Packet switching wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Routing in delay-tolerant networking wikipedia , lookup
Networking Review 1. What is the difference between a circuit-switched network and a packet-switched network? 2. What is the difference between broadcast and multicast? 3. Write down the seven layers of the protocol stack in ISO OSI Architecture in proper order. 4. What is the job of the network layer? Give an example of a network layer protocol. 5. Define the following terms: open network, closed network, proprietary network, MAN, LAN, WAN, bridge, repeater, switch, router, gateway, backbone. 6. Explain the hidden terminal problem for wireless networks. What is a solution? 7. At what layer in the TCP/IP protocol hierarchy would a firewall be placed to filter messages based on a. Message content b. Source address c. Type of application 8. What is the internet2? Give an example that motivates its creation and use. 9. Translate the IPv4 address 192.207.177.133 into 32-bit binary. 10. List 3 of the most commonly used internet application protocols, and tell or illustrate how they work. 11. Why is telnet considered an insecure protocol? 12. Why does internet radio require a different protocol from other applications? What is the most successful protocol? 13. Explain the difference between client/server and peer-to-peer interprocess communication. 14. Explain how HTTP works with an example. 15. Encode the following binary patterns in dotted decimal notation. a. 0000 0001 0000 0010 0000 0011 b. 1000 0000 0000 0000 c. 0001 1000 0000 1100 16. What is the Manchester encoding scheme? How does it work? 17. Suppose a 128-Kbps point-to-point link is set up between Earth and a rover on Mars. The distance from Earth to Mars (when they are closest together) is approximately 55 Gm, and data travels over the link at the speed of light 3 × 108 m/s. a. Calculate the minimum RTT for the link. b. Calculate the delay × bandwidth product for the link. c. A camera on the rover takes pictures of its surroundings and sends these to Earth. How quickly after a picture is taken can it reach Mission Control on Earth? Assume that each image is 5 MB in size. 18. Calculate the total time required to transmit a 1.5 MB file in the following cases. Assume an RTT of 80ms, a 1 KB packet size and an initial 2 x RTT handshake before data is sent: a. Bandwidth is 10 Mbps, data packets can be sent continuously. b. Bandwidth is 10Mbps, but after each packet we must wait 1 RTT before sending the next one. c. Link allows infinitely fast transmit, but limits bandwidth to only 20 packets per RTT. d. Link is infinitely fast as in (c), but we can send 1 packet in the first RTT, 2 in the second, 4 in the third, etc., with exponential increase each RTT. 19. Suppose TCP operates over a 40-Gbps STS-768 link. a. Assuming TCP can utilize the full bandwidth continuously, how long would it take the sequence numbers to wrap around completely? b. Suppose an added 32-bit timestamp field increments 1000 times during the wraparound time you found above. How long would it take for the timestamp to wrap around? 20. Suppose we wanted to transmit the message 1011001001001011 and protect it from errors using the CRC8 polynomial x8+x2+x+1. a. Use polynomial long division to determine the message that should be transmitted. b. Suppose the leftmost bit of the message is inverted due to noise on the transmission link. What is the result of the CRC calculation? How does the receiver know that an error has occurred? 21. Suppose we have the forwarding tables shown below for nodes A and F. Assume that all links have cost 1. Give a diagram of the smallest network consistent with these tables. Node B C D A Cost 1 1 2 NextHop B C B E F 3 2 C C Node A B C D E F Cost 2 3 1 2 1 NextHop C C C C E 11. Suppose a router has 3 input flows and one output. It receives the following packets as listed below all about the same time, in the order listed. Assume the port is busy, but all queues are otherwise empty. Give the order in which the packets are transmitted, assuming: a. fair queuing b. Weighted fair queuing, where flow 2 has twice as much share as flow 1, and flow 3 has 1.5 as much share as flow 1. Any ties are resolved in the order flow 1, flow 2, flow 3. Packet 1 2 3 4 5 6 7 8 Size 200 200 160 120 160 210 150 90 Flow 1 1 2 2 2 3 3 3