Future Research

The switching behavior of MultiNet augurs badly for TCP performance. MultiNet is implemented below IP, and so TCP sees fluctuating behavior for packets sent by it. It receives immediate acknowledgements for packets sent when the network is active, and delayed acknowledgements for buffered packets. The above behavior affects the way TCP adjusts the RTT for the session, and from the way it is calculated, the RTT will always be an upper bound. An overestimate of RTT results in larger timeout values to ensure that packets are not lost. However, a larger than required RTT has other consequences with respect to flow control, and congestion response. This problem is generally relevant for networks that have periodic connectivity. A solution to this problem has to mask the delay encountered by the buffered packets. We are currently exploring ways to achieve this, and improve TCP performance.

As stated previously, we do not consider scenarios when a MultiNet node is participating in a multihop ad hoc network. The synchronization problem is complicated for such scenarios. A scheme that supports multihop networks has to handle partitioning issues of the ad hoc network, and ways to resynchronize it. We are exploring different randomization schemes to ensure probabilistically good synchronization among nodes.