[802.3_NGECDC] EthType on Long Reach

[Robert Moskowitz <rgm@xxxxxxxxxxxxxxxxxxxx>]

In a conversation I had about the Long Reach work, there was a comment 
that not all sensors want to add IP, even with the work in IETF's 6lo 
for IPv6 over MS/TP (Bacnet).

Is there an EthType that is used for directly-on-mac messaging, or one 
lying around from the old days that was used for this?

Something that basically says here is a message that you know how to 
handle?  Or looking at it in the ISO stack model of layer 5 (session) 
directly on layer 2.  I will point out that is also basically what 
CANBus is.