[Guy Harris <guy@xxxxxxxxxx>]

> I notice that although tcpdump understands decnet/LAT, ethereal does not.
> (nevermind where I saw that kind of traffic..) Since I know the ether payloads
> for some unimplemented traffic (0x6004 for LAT and 0x8038 for LanBridge) I
> starting looking at what I'd need to do to make a decoder..

Well, the first thing you'd need for a LAT decoder would be a
specification of the LAT protocol...

...unfortunately, DEC have never published it.

In fact, the LBL version of tcpdump *doesn't* understand LAT - all it
does is hand off packets with an Ethertype of ETHERTYPE_LAT to the
default printer.

DECNet, on the other hand, is documented; see

	http://gatekeeper.dec.com/pub/DEC/DECnet/PhaseIV/

(which says:

	At the same time that DECnet Phase IV was released, Digital
	introduced a new LAN based protocol for terminal access called
	LAT (Local Area Terminal).  This protocol was revolutionary and
	Digital was awarded a patent for it.  LAT remains to this day a
	proprietary protocol for which specifications are not available
	without license.).