[rbridge] PS issue #11

[Spencer Dawkins]

I apologize for not sending mail on this issue when it confused me the first 
time...

Just to be clear (to me?), when we talk about

#11 internal/external, inside/outside terminology
    there is one objection to these terms as topological;
    the draft intends to define them sufficiently
    does this need to be addressed further?

In the following picture (constant-width fonts will help a lot on this), 
assume that "b"s are bridges, "r"s are rbridges, and "e"s are end stations. 
Are the set of bridges connecting to e1 part of the same spanning tree as 
the set of bridges connecting to e2?


e1 -- b --- b ----------- b
        \   |             |
          \ |             |
            b --- r ----- r
                  |       |
                  |       | (rbridge campus)
                  |       |
                  r ----- r -- b -- b
                  |               \ |
                  b --------------- b -- e2


In the following picture, are the (inside?) bridges in the middle of the 
rbridge campus part of the same (outside?) spanning tree, or does what 
happens inside the campus show up outside the campus?


e1 -- b --- b ---------- b
        \   |            |
          \ |            |
            b -- r --b-- r
                 | /   \ |
                 b ----- b (rbridge campus)
                 | \   / |
                 r --b-- r -- b -- b
                 |               \ |
                 b --------------- b -- e2

All clues are graciously accepted!

Thanks,

Spencer