[c-nsp] TE design guidance

[Justin Shore]

I'm trying to come up with the best way to layout TE tunnels between a 
couple POPs.  On one side I have a pair of 7600s with 3BXLs running 
SRB1; we'll call this A and B.  On the other side I have a pair of 
ME6524s; we'll call these C and D.  Each pair of routers serves are the 
core in their respective POP, with the edge devices dual-homing to each 
core router.  The first router in each POP is connected via GigE over 
about 80 miles of fiber through numerous towns using media converters. 
The second router in each POP is connected in a similar fashion over 
another strand in the same fiber bundle.  A 3rd connection is being made 
with radios and will terminate in the first router in each POP.  At some 
point in the future the second fiber path will be broken in the middle 
to drop off services in that town.  I anticipate either a 7201 or 
another 7600 depending on bandwidth needs vs costs; we'll call this 
future router E.

My short term needs mainly involve FRR.  However as our backbone 
bandwidth needs grow we'll likely need the full set of TE features in 
the not-too-distant long-term.

Unfortunately we do not have 2 diverse fiber paths to work with at this 
point in time.  My initial thought was that I should build tunnels for 
A-C, B-D, A-B-D-C, and B-A-C-D.  However the radios complicate that 
design in my eyes.  How do I indicate that the radio path is more costly 
than the fiber path for as far as MPLS TE is concerned?  Do I need an 
explicit path defined for each possible combination of paths?  Am I 
simply not looking at this in the right light?

Thanks
  Justin