Subject: TORA details

From: Gregg Horan <[email-masked]>
Date: Tue, 22 Feb 2000 17:08:58 -0500

I am doing some research for a paper regarding the current state of the
MANET routing scene.  The information that I am compiling is simply a
discussion of some of the approaches being implemented followed by some
specific examples and a discussion of some of the simulations and
testing that has been performed.

That said, I have a short question that I was hoping someone on this
list might have a moment to address.  Let me preface this by saying that
I am not doing any *research* per se, and my expertise in the area is
comprised solely by what I have read over the past few weeks.

My question (and confusion) lies with TORA.  

As I understand it, a successful route request will generate numerous
routes from a source node to a given destination node.  These routes
aren't stored in a standard distance vector or link state method, but
they rely on assigned weights for each node to dictate a direction of
each link.  I can easily visualize how this 'trickle-down' approach,
with the source at the highest level and the destination at the lowest
(0), would allow multiple routes for packets to find their way from the
initiating node to the destination node.  

What I am unclear about is, if node A has completed a route request
phase to gain a path to node B, how does node A determine a route to any
other arbitrary node C?  The only solution that I can come up with is
that node A would have to re-broadcast and come up with a completely new
directed graph with respect to C... thus invalidating the old routes to
node B.  Without the route caching or routing tables of most of the
other protocols, this would seem to be highly ineffective.

If anyone could clarify this... whether I am interpreting it
incorrectly, or simply underestimating the effectiveness.

Thank you all for your time.
(please feel free to respond directly to [email-masked], as this is
probably of no great interest to the list at large)
Gregg Horan