[nsp] MPLS advice

[Matt Bazan]

This may not be a little off topic, if so, my apologies.

I'm looking for opinions / caveats and general thoughts on replacing our
WAN with a MPLS solution .  

Here's a little background on our current WAN:  we have 18 office
branches spread throughout California that are connected via full T1's
in a hub and spoke architecture.  We have 4 hubs with 4 - 5 branches
hanging off each one.  This is provisioned with full T1's between the
hub and spoke (as many of these T1's don't cross LATA's we're paying
~$500 each.)  However, this is more bandwidth that we need (on the order
of 1mb per circuit too much), and  for reliability / performance reasons
we'd like to move away from the hub and spoke design.  

At present we are looking to replace this design with a more scaleable,
cost effective plan that has full mesh connectivity between the
branches.  From what I've been reading, an MPLS solution seems to fit
the bill.  As our current carrier for the T's is AT&T we'll probably
stay with them for MPLS - if we go that route.  The plans we have seen
from AT&T are for their managed MPLS solution.  As I understand it this
essentially means our existing T1 circuits will be switched over to
AT&T's MPLS cloud leaving us with very little to change or manage on our
routers.  This is an attractive feature for us.  We're also hoping to
move to a fractional T1 pipe and realize some bandwidth savings with
this approach.  

Comments from anyone?  Concerns or issues that I should be aware of?
Thanks all.

  Matt