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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

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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

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

Richard Hartmann: Overlay-based IP Routing 2

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

Richard Hartmann: Overlay-based IP Routing 3

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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

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Routing scenarios

Simple case: routing between participants

h i rn r 1

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Routing scenarios

Slightly more complicated: routing to non-participant

h rn r 1

1

h x

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Routing scenarios

Advanced: routing between participating networks

h i rn r 1

1

h i 1

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

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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

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

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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

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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)

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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

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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

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

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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

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Outline

1

Motivation for Overlay-based IP Routing

2

Considerations

3

Preliminary results

4

Tasks

5

Timeline

Richard Hartmann: Overlay-based IP Routing 17

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Timeline

September: orientation October: design decisions & proof of concept November – December: proper implementation December – January: writing the DA

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The end

Questions?

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