1. Kris, Karthik, Ansley, Sean, Jeremy Dick, David K, Frans, Hari
DHT Routing
Kris, Karthik, Ansley, Sean, Jeremy Dick, David K, Frans, Hari

2. Churn
Dealing w/ faults & failures
App interface
Proximity & topology
Today’s Internet
Tomorrow’s Internet
Security

3. Churn Given: Evaluate performance in terms of:
Churn model and rate
Bandwidth consumption
Application workload
Evaluate performance in terms of:
Lookup latency
Insert latency
Q: How do different techniques & protocols compare along these axes?
What works best under each set of conditions?
Example
Structured DHT routing v. unstructured
Do “ultra peers” make sense?
One-hop routing v. log N routing + aggressive caching

4. Dealing with faults & failures
Network partitions & failures
Healing strategies
Coping with non-transitive Internet routing
Large discrepancies in node-to-node performance
Mechanisms for choosing alternate paths when failures are detected?

5. Application Interface
Generality
How independent can applications be of DHT routing, and get acceptable performance?
Should we study application-specific DHT routing?
Should we shoot for one big DHT?
Iterative v. recursive resolution
Move the data through the overlay or not?
Evolving the API from IPTPS-II
k of N API
Degree of redundancy in routing paths
Traffic priorities within DHT

6. Proximity and topology
Picking good Internet paths
Picking good placement points
Goal: Good performance & failure resilience
What DHT techniques can be used?
Scalable probing, synthetic coordinates,…
What can the IP layer tell us (e.g., mapping info -- IP-layer topology, past failure statistics info, link bandwidths, etc.)

7. Interacting with today’s Internet
Coping with network reality
Coping with ISPs blocking/limiting P2P
Coping with middleboxes, NATs, firewalls…
Helping them cope
Traffic engineering
Congestion control, traffic prioritization within DHT
P2P proxy caching
Many coexisting, potentially competing

8. Internet architecture
Q: Can DHTs help evolve the Internet architecture?
Location-independent naming
Use DHTs to enable informed application routing (e.g., weather service, outage avoidance, etc.)
Stitching the Internet back together
Across NATs, firewalls, middleboxes
Do DHTs need policy routing?

9. Security
See security group