Recitation Active vs Passive Active vs Passive measurements

Recitation

Active vs. Passive • Active vs. Passive measurements. Explain what they are – Describe an active measurement experiment that measures something that can not be measured by passive approaches – Describe a passive measurement methodology that measures something that can not be measured by active approaches

Traceroute • Explain how traceroute works. Explain why we sometimes send UDP and not ICMP packets. • One traceroute experiment gave us the following graph: Src->L->A>D->D->Dst. Do you notice the circle in D? Why is there? A Src B L D Dst C • Descrribe how the graph Src->L->C->B->Dst can be acquired from the topology above

DNS • What is DNS? How is it used? • How can we use DNS to implement Content Delivery Networks? • CNN website contains the following URLhttp: //i 2. cdn. turner. com/cnn/dam/assets/14 0509111657 -russia-victory-day-parade-t 1 main. jpg. Describe the DNS translation steps • Describe the issues raised to CDN, if we use 8. 8 as DNS server

Packet switching • Describe the differences between packet switching and circuit switching • Why is packet switching better? • Why didn’t telephone use packet switching?

Packet loss • You’d like to find the packet loss in each link of a network. How can you do it? A B C

Packet Dispersion • Explain how to use packet dispersion to measure bottleneck link capacity