CS 268: Project Suggestions Scott Shenker and Ion Stoica (Fall, 2010) 1

2 Overview Will present 19 project suggestions Legend: based on how well-defined projects are, not necessary how difficult they are Well-defined projects Less-defined project You need to define project Need to send us a one page proposal by Sep. 22 Feel free to talk with us beforehand! (in fact, we insist!)

3 Outline Wireless Software-Defined Networking Congestion Control Security Economics Datacenters Network architectures

Wireless

Rapidly fluctuating networks Design a routing algorithm that is targeted at networks where the link quality fluctuates rapidly Fast compared to global recomputation time Slow compared to packet transit times Graph relatively stable (i.e., not about mobile nodes) Tradeoff between efficiency and performance Flooding is a baseline: inefficient, but packets arrive! Are there theoretical limits on performance? Is there a literature on this problem? 5

Network Coding How well does it work, and why? Revisit SIGCOMM 2006 paper on topic Performance w/ TCP and w/o TCP quite different Look at different load patterns, identify what conditions make network coding work well 6

Software-Defined Networking

NOX at home Build a simple system that people can use to manage their home network: Implicit identification Easy access control Security measures (identify bots, limit spam, etc.) Internal debugging External debugging Etc. Not rocket science, but could be widely used! 8

Analysis of SDN Can one theoretically characterize SDN: Complexity? Reliability? Performance? Compare to current distributed approaches… 9

Congestion Control

Dueling Diatribes Respond to Bob Briscoe In public 11

Blending Paradigms Can one combine the “fairness” religion with the “pay-for-congestion” religion? One can consider two timescales: Fairness on short timescales Payment on longer timescales (for “share”) Are FQ and Kelly just extremes along a sensible continuum? 12

Datacenter Implosion Is the problem real? Come up with another solution to the problem 13

Decongesting the Datacenter Decongestion: great idea whose time never came Datacenters: new context where deployment might be possible Is this a good marriage of opportunity and answer? 14

Security

Phinishing Phishing Simple method to address phishing: Ask people who they think they are talking to! Build a prototype system for this Limit number of user interruptions Identify what new global services are needed 16

Living with Secure Hypervisors Assume that every host has a secure hypervisor What does that mean for security? Not-a-bot VDC What else can we do? How would this change the world? 17

Living in a Google World The existence of large-scale infrastructures like Google allows us to assume that there are Internet-scale systems that can deploy new services. How does this change: Security? Deployment of new architectures? Test case: deployment of flat names 18

Economics

Network Neutrality Is the Google-Verizon pact a good thing? What does this mean for the future of the Internet? Can you back this up with a model? 20

Datacenters

Comparison of Datacenter Routing Topologies Many datacenter routing topologies proposed so far Portland, VL2, BCube, … Compare these proposals in terms of Scale and incremental scaling Number of ports Wiring … Questions Is there one answer? If not, when should we use a topology and when should we use another? 22

TCP for Datacenters TCP not adequate for datacenter environments Very low latency, high link capacity, low loss rates Optimize TCP or invent another flow control protocol to Reduce impact of packet loss Optimize flow-start … You can assume router/switch support See DCTCP paper at SIGCOMM’10 for related work 23

Cross-Layer Optimization for Datacenters Widely different workloads Latency-bounded requests (e.g., search queries) Large file transfers (e.g., data replication) How could you optimize the transport protocol if you knew the type of traffic? E.g., avoid slow-start for short latency bounded-requests What would be the mechanism to pass application “hints” to transport layer? [Optional] How would you “protect” the transport layer against misbehaving/malicious applications? 24

QoS in Datacenters QoS has mainly failed in the Internet Is there a case for QoS in datacenters? If yes, what is the service model? Reservation? (Weighted) Fair sharing? Differentiated service? What are the challenges? 25

Small-Scale Multicast Data replication: common workload in datacenters E.g., GFS, HDFS, a block is replicated two or more times Optimize this communication pattern Design a multicast solution for a small number of receivers, e.g., no more than 10 Challenges: Which layer? Flow control Reliability 26

Network architectures

28 Burst Switching Two main communication models Datagrams: each packet is individually switched (routed) Circuits: a circuit is set-up and all packets are forwarded Hybrid model: burst switching First packet describes how many packets are in a burst Router decides whether to forward all packets in the burst or none of them Research Design a burst switching protocol and study its trade-offs

Caching Everywhere Assume There is caching in every router and switch 90% of traffic will be video by 2013 (CISCO report) Questions What is the impact on backbone traffic? What is the impact on ISP policies? Study Assume different video access patterns See us for possible traces 29

30 Next Step You can either choose one of the projects we discussed during this lecture, or come up with your own Pick your partner, and submit a one page proposal by September 22. The proposal needs to contain: The problem you are solving Your plan of attack with milestones and dates Any special resources you may need