BOOM! there goes WorldCom

There is someting called "Sonet" out there, if provisioned as 1+1, eg
a backup path for each primary path it's capable of switching your
circiuts into the protect path in less than 100ms...

So, when getting capacity make sure that it is provisioned over
1+1 sonmet and thet the local loop also is redundant and thet you
get a primary and protect router.