Single overlay capable of achieving multiple communication services over a P2P network
The paper comes up with a single infrastructure capable of supporting several services such as multicast, broadcast, anycast, mobility etc over the Internet architecture with was built to be P2P. It achieves this by introducing a level of indirection in the form of nodes that act as i3 servers. Senders direct outgoing messages to identifiers instead of a particular destination node address. Receiving nodes can then subscribe to these identifiers if they wish to the message. Hence, more than one receiver can subscribe to an identifier, thereby allowing for the above mentioned services to be achieved over a P2P network. This method suggested by them provides for a lot of flexibility in the terms of the types of services that can be provided, nodes that can add or drop themselves to a service, etc. Other than providing for these services, their structure achieves security (in some aspects, while giving rise to different set of security concerns that they consider in detail and provide methods to counteract) which couldn’t have been achieved in a P2P system.
Methods to add new nodes, handle failure of old ones and provide efficient routing
In addition to suggesting the basic infrastructure, the paper also talks of efficient methods implementation of the idea. The first question that comes to mind when the i3 structure is suggested is, the overhead it would add. The paper provides for a method of packet forwarding that seems to add minimal overhead. In the method suggested, the senders cache the address of the server that is responsible for routing packets to the identifier the sender wishes to send packets to. This reduces the time to find the server for subsequent sends. The receivers reduce the time to receive packets from the servers by choosing servers close to themselves. Similarly, the paper also suggests efficient methods to deal with node failures, node additions and packet forwarding.
Methods to handle security threats
The nature of how the i3 system works exposes it to several security threads. The paper makes a detailed analysis of all possible threats and suggests methods to counteract them.
PROBLEMS
The paper claims that it handles the triangle problem by getting the receiving nodes to choose a server close to themselves to store the trigger containing their id. However, this solution only works if the system has a large number of i3 servers. If there exist only a few servers for a large number of nodes, it is likely that two nodes, adjacent to one another, might have to communicate with a far away server node to be able to reach one another.
Several of the methods they suggest to handle the issue of security work by inhibiting free and flexible use of i3 by the servers. For eg, one of the methods limit the number of triggers a node can have. Also, the innate structure of i3 introduces far too many means of intrusion to be able to detect and counter every one of them.
In spite of several methods to reduce overhead, the structure still introduces them at various stages and steps. There is the overhead introduced by in the security methods suggested, enabling caching by the appropriate server sending out the, “it is me you want to send future messages to” message, etc.
FUTURE WORK
It seems like i3 would provide a workable and efficient platform for a network of rapidly moving nodes. it seems to have the mechanisms in place to provide support for such a system. Work could be done to explore possibilities in the area.
