NRL advances mobile-routing protocol
A network can be difficult to maintain if router performance comes and goes at random intervals. Most IP routing techniques rely on relatively static router configurations that work fine in most environments, but their stability might not hold up when used with mobile devices in combat or other highly dynamic scenarios. So Naval Research Laboratory researchers are helping develop a set of routing protocols for setting up Mobile Ad-hoc Networks (Manet).
NRL researcher Joseph Macker, who started work on Manet almost two decades ago, is co-chairman of the Internet Engineering Task Force's Manet working group (GCN.com/1008), which includes engineers from Motorola, Juniper Networks, Cisco Systems, Johns Hopkins University's Applied Physics Laboratory and other research institutions.
Macker said the Manet architecture involves building a routing table in which each node knows not only its neighbors one hop away but also the nodes next to those neighbors. Together, the nodes generate routing tables that can efficiently send packets through the topology.
A Manet can work in reactive mode, in which the route is determined only when the network must convey a packet, or in proactive mode, in which the nodes confer to build routing tables regardless of traffic. Proactive networks can convey traffic more quickly, but they involve more processing and bandwidth overhead.
One of the new Internet drafts is on a Neighborhood Discovery Protocol that allows nodes to discover and work with those one and two hops away. A second one is on efforts to build a packet format capable of carrying multiple messages. A third one, about the Management Information Base, describes a set of tools for configuring and managing routers on a mobile network.
Researchers at the working group meeting have also unveiled some Manet test cases and prototype implementations.
NRL has developed a C++ library that will allow developers to package and unbundle Manet packets. The library works with standard networking interfaces such as sockets, timers and routing tables (GCN.com/1009).
In addition, other researchers described implementations of Manet Optimized Link State Routing, a protocol for building link tables for ad hoc networks, including those built at France's l''cole Polytechnique laboratory and Japan's Niigata University.