[c-nsp] segment routing/evpn on ASR920

[Aaron Gould]

I read that SR/SPRING is an alternative to LDP or RSVP... seems that
SR/SPRING is a label distribution protocol.  Meaning, in my mind, it's a way
to learn labels...mpls labels I guess.  If so, would we refer to EVPN as
EVPN-SR?  If so, would it follow that a non-sr network, one that has
employed ldp for label learning, with evpn, would be referred to as EVPN-LDP
?  I'm not thinking so.

Further, I recall reading that EVPN is Control Plane, and has a few
different options for Fwd'ing plane...

EVPN-VXLAN
EVPN-PBB
EVPN-MPLS
...perhaps others...

Tom, I wonder if we/you should look for ASR920 docs/support for EVPN-MPLS in
your desire to see if EVPN will work over SR?

I could be way off.  

-Aaron