[c-nsp] Best practice, MPLS and MTU settings

[Adam Vitkovsky]

The higher you can get the better. 

You don't want to restrict your MPLS pipes unnecessarily. 
In case your platform counts L2 overhead into MTU leave some space for
future L2 overheads (802.1ah) / label stacks (Segment Routing) and leave the
rest for your customers. 

See in case you'll provide carrier-ethernet services for Nick or myself we
would require MTU 9100 so that we can still offer MTU 9000 to our customers
in that particular region. 


adam