1. Rapid Mobility via Type Indirection
Ben Y. Zhao, Ling Huang, Anthony D. Joseph, John D. Kubiatowicz
Computer Science Division, UC Berkeley
IPTPS 2004

2. Rapid Mobility large-scale mobile deployment becoming a reality
wired network
IPTPS 2004

3. Our Approach Warp: mobility infrastructure on structured P2P overlay
route using in-network indirection
directory service API (DOLR): RouteMsgToObject(ObjectID, Data)
treat mobile nodes as objects on their proxy
Flexible hierarchy for fast handoff
layers of overlay forwarding hops
longer hops in wide-area, shorter hops in LAN
implicit hierarchy: only modify short hops if moving locally
Aggregate control traffic for mobile crowds
“elect” mobile trunk node to tunnel traffic for others
reduce control traffic to one handoff per crowd
Routing, hierarchy, aggregation all managed by P2P protocol
IPTPS 2004

4. Decentralized Object Location & Routing
Decentralized directory API on structured peer to peer overlays
Server “publishes” object: overlay distributes location pointers to log(n) nodes
Clients route message towards object’s ID, redirect when location pointer found
Performance from locality-aware routing and local convergence properties
IPTPS 2004

5. Registration / Routing
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6. Fast Proxy Handover
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7. Mobile Crowds mp mp mp mp
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8. Type Indirection
Overlay Node
Proxy node
object on
static node
Register / Handoff … …
Mobile Node
Mobile Node
Mobile Node
Mobile node
Mobile Node …
J o i n / L e a v e
Mobile node
object on
mobile node
leaf
Mobile Crowd
trunk
Type Indirection
Leverage built-in indirection in object location layer of DOLR
Can further iterate type indirection: e.g. PDAs on train passenger
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9. Routing Performance compare warp to Mobile IP
add redundant root to reduce end to end latency
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10. Handoff Latency
compare time for Mobile IP, Warp and Warp full convergence
IPTPS 2004

11. Related Work Fast handoffs Session mobility (Snoeren00)
hierarchical handoff (Caceres96)
hierarchical Mobile IP (Perkins96)
incremental route establishment (Keeton93)
Session mobility (Snoeren00)
ROAM (I3) (Zhuang03)
in-network traffic redirection pointers (triggers)
can do hierarchical mobility, node aggregation
placement of triggers up to mobile node
IPTPS 2004

12. Summary Flexible name-based hierarchical mobility
treat mobile nodes as “objects” on overlay proxy
routing protocol manages traffic redirection points
virtual paths eliminate home agent and triangle routing
no notion of “home network”
Aggregation to reduce control traffic
treat leaf nodes as “objects” on mobile trunks
Self-managing network redirection
rely on self-organizing protocol for aggregation, hierarchical handoff, fast route establishment
protocol adapts to node failures, topology changes
IPTPS 2004

13. Comments, questions? http://www.cs.berkeley.edu/~ravenben/tapestry
Thanks…
Comments, questions?

14. Handoff Load
IPTPS 2004