The main contributions of this paper are:
- Indirection: the authors discuss how decoupling of the sender and receivers helps to generalize point-to-point communication. i3 provides better mobility, multicast, and anycast through this indirection. i3 identifiers and triggers serve to achieve this level of indirection.
- The paper proves the flexibility of overlay networks. It further provides valuable techniques to build security, scalability, availability, fault tolerance, and improved performance on top of the overlay. Overlay also allows for incremental deployment of i3 in a network.
- The authors provide many novel ideas such as using a stack of i3 identifiers to achieve service composition on top of i3, heterogeneous multicast (where receivers choose to receive different flavors of the multicast data), and fault tolerance (if one identifier fails, try the next identifier).
Glaring problems: The paper is well written and many scenarios are well thought of, however, the authors provide no experimental results for the applications of i3 most discussed in the paper: multicast, anycast, mobility. The paper goes at length to describe how i3 eases multicast, but does not provide evidence about i3’s efficiency when dealing with these. Additionally, it is my understanding that i3 would make unicast quite slow, so it would not be a suitable replacement for existing network infrastructue.
Future research: it would be interesting to implement a hybrid approach where packets are not required to go through an i3 node. Also implement i3 servers as modified switches. That is, modify a network switch to work with i3 triggers and identifiers instead of IP packets. If a switch can be made like this, a lot of the overhead from processing the triggers in software is taken away.
