APS is not intended to be a standalone protection factor. Implemented on
routers, it will only protect you up to the first LTE. In most cases, this
will be an in-house cross connect.
Worse, in my miserable experience, the APS would flip back and forth.
It's not supposed to, but it has. I firmly recommend: do not pay for
APS. Put the money toward diverse paths. As usual, Paul Vixie has got