[c-nsp] Layer connection

[harbor235]

So here is my scenario, I have a primary Internet gateway service at
location X
and a backup gateway service at location Y. To add resiliency to my design I
am
thinking about adding a layer 2 device into the mix at location X that uses
a large
SP layer 2 service connecting the two sites at layer2. This layer 2
connection allows me to speak
Ethernet to the remote POP extending my iBGP mesh and providing added
resiliency
in certain failure scenarios.

My question is has anyone used such a service? Does it work well? any
issues?
My initial thoughts: does a remote failure at the POP result in a link down
status
on the other end of the L2 circuit? How is spanning-tree (if its on) behave
when endpoints
are potentially 100's of miles apart? convergence issues? spanning-tree
tweaking?

thanks as always,

Mike