[c-nsp] Link encryption and scalability kit etc

[Alan Buxey]

Slightly larger frames and a bit more config.  In terms of throughput its line speed or near enough to not distinguish....we're doing it on 10Gb links. 

Be aware though that any WAN carriers that might be doing tagged MPLS stuff have to support the protocol.... our initial circuit was such and MACSEC didn't work - temp fix was ipsec/gre. 

alan