On Thu, 12 Jan 2012 00:03:50 +0100, you wrote: TOPS-20 Network Configurator for DN20, Version 4A(11) That seems to be ANF-10 (Advanced Network Functions) protocol configuration utility. ANF-10 was a TOPS-10 thing only so this should not be the case. Instead I think that Johnny is correct when he writes that the thing Joe pasted seems only related to DECnet over DTEs like synchronous links, not Ethernet. I had very little experience with TOPS-20 and from what I see it was quite different on TOPS-10. But I would certainly look for DECnet-20 and I would not expect more than phase III. I'm sure that DECnet-20 V4 did Phase IV too. :) G.