Internet Indirection Infrastructure

Summary

This paper describes an overlay network called Internet Indirection Infrastructure (i3) that is designed to easily provide services like multicast, anycast and mobility. i3 adds a level of indirection on top of the current network, separating the act of sending and receiving from each other. Rather than sending to one or more IP address, a sender will send to an logical identifier. Receivers will indicate which identifiers they are interested in receiving by way of triggers.

i3 was designed to be versatile, allowing users to create services like mobility, anycast and service composition on it. It also decentralized the responsibility for creating efficient trees by delegating that task to the end-hosts.

i3 uses a rendezvous-based communication. Each packet is represented by a (id, data) pair where id is an m-bit identifier and data is the IP packet payload. Receivers send out triggers of the form (id, addr) which states that all packets with an identifier id should be sent to addr. When a receiver would like to receive data, it can put out a trigger in the network. And, then when a packet with that id arrives, it will get sent to the receiver.

The authors implemented and evaluated i3 using the Chord lookup system. Initial evaluations suggest that i3 is highly flexible and can support many sophisticated applications.

Critique & Questions

Interesting paper. The rendezvous-style communication they used is fairly straightforward. Although from a practical implementation standpoint, there do seem to be many challenges to work through before that can take place. I liked that they acknowledged if/how i3 could be implemented for real.