Overlay-based IP Routing Richard Hartmann Chair for Network - PowerPoint PPT Presentation

Overlay-based IP Routing Richard Hartmann Chair for Network Architectures and Services Department for Computer Science Technische Universit¨ at M¨ unchen November 10, 2010 Richard Hartmann: Overlay-based IP Routing 1

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 2

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 3

Motivation Route around failure conditions New prefixes/AS numbers Stale routes Routing loops Defective routers in the backbone Deliberate null routing Avoid saturated links Load-balancing Test-bed for routing mechanisms On demand & event-driven DHT-based with cached results Secondary considerations Firewalls NAT Censorship Richard Hartmann: Overlay-based IP Routing 4

Routing scenarios Simple case: routing between participants r n r 1 h i Richard Hartmann: Overlay-based IP Routing 5

Routing scenarios Slightly more complicated: routing to non-participant r n r 1 h h x 1 Richard Hartmann: Overlay-based IP Routing 6

Routing scenarios Advanced: routing between participating networks r n r 1 i 1 h h i 1 Richard Hartmann: Overlay-based IP Routing 7

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 8

Considerations Scalability Routing database must scale Routing decisions need to be fast Efficiency Low system overhead Good bandwidth utilization Resilience Self-regulating Constant self-monitoring Dynamic creation & destruction of tunnels Usability Easy to use Transparent to programs High bandwidth Low round trip times Low jitter Routing to nodes within and without the overlay network Richard Hartmann: Overlay-based IP Routing 9

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 10

Preliminary results Confirmed decision split into separate overlays for routing decision and data transmission Use Pastry for routing decisions Use IP GRE for data transmission Richard Hartmann: Overlay-based IP Routing 11

Preliminary results Why Pastry? Suggestion by Ralph to Nils Full framework with modular structure for DHT, file storage, chat, web cache, content distribution, others Built-in simulator with reliable results Allows tweaking of internal routing metrics Discarded alternative: Kademlia DHT only Simulated results are different from real-world tests (Ali) Richard Hartmann: Overlay-based IP Routing 12

Preliminary results What is GRE? Generic Routing Encapsulation We are using it for IPv4 Creates a tunnel interface for routing purposes Sending/receiving through tunnel interface will add/strip extra header: IP header of encapsulation GRE header Version Encapsulated protocol Sequence number Checksum Encapsulated paket/datagram Richard Hartmann: Overlay-based IP Routing 13

Preliminary results Why IP GRE? Extremely efficient implementation in Linux Kernel (1-10 Gbit/s full duplex on commodity hardware) Well-established technology Low overhead on nodes No scaling issues Richard Hartmann: Overlay-based IP Routing 14

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 15

Tasks Implement IP GRE routing policies and templates Enhance Pastry Code cleanup IPv6 support? Implement event-driven routing Implement DHT-based routing Test Kammenhuber’s ideas Perform tests & measurements Summarize findings in paper Richard Hartmann: Overlay-based IP Routing 16

Outline Motivation for Overlay-based IP Routing 1 Considerations 2 Preliminary results 3 Tasks 4 Timeline 5 Richard Hartmann: Overlay-based IP Routing 17

Timeline September: orientation October: design decisions & proof of concept November – December: proper implementation December – January: writing the DA Richard Hartmann: Overlay-based IP Routing 18

The end Questions? Richard Hartmann: Overlay-based IP Routing 19