We get it. LISP works. It sounds neat. BUT!

The topic that I don't see Cisco talking much about is how this works with all the sites that aren't doing LISP. Big enterprise WAN, fine, can do internal LISP. Internet, not so much.

Why and when will ISPs provide PITR services? I can see companies doing LISP to optimize inbound traffic to their Internet-facing apps. I can't see them investing in LISP in the hope it'll optimize their outbound traffic to other sites. And why would the ISPs want to buy a lot of LISP-capable big iron to provide PITR services? Bit of a chicken and egg problem?