It would be nice if topologies could be mapped to graphs -- and it may well be possible, even though I personally don't know how to do it. (Alternatively, I suggested to our mathematicians many years ago that I suspected that Matrices may be a more appropriate representation for MANET networks than graphs, but they were not interested enough in this suggestion to see whether it had any merit or not.)
However, I'd like to point out that for any large network the topology (or graph) is not fully known from any arbitrary point within the structure. For large networks, we need abstraction to enable scaling. Also, those of us who work with MANET technologies are quick to point out that topology is also a function of time in that topology (and therefore its graph, if we could draw it) is also a partial function of the 4 dimensional geographic system (x, y, z, time) in which it exists. I suspect that this is why arcs proved useful in the discussions which Noel alluded to below -- arcs provide a mechanism to represent abstraction. -----Original Message----- From: Noel Chiappa [mailto:[email protected]] > From: Tony Li <[email protected]> > for the most part we seem to be using locators to name the edges of the > graph, not the nodes. All depends on how you model the network! Are the graph-nodes interfaces, and the networks the arcs (this requires multi-drop arcs, of course), or are the networks the nodes, and interfaces the arcs? The latter is what it-whose-name-I-don't-like-to-utter originally did, but that meant we had to have attributes on the arcs, which after some thought I decided was excess hair. That's because it turned out that when you started thinking about what data you needed, arcs started to look a lot like nodes, at least in terms of the data structures. So that led to the next step - make everything (networks, interfaces, etc) a graph-node; you wound up with a graph with attribute-less arcs, which only indicated connectivity. (I.e. the data structure for node X says "I am connected to nodes A, B and C", etc - there are no actual arc data-structures.) <snip> _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
