It does not appear that the VMS phone protocol was ever officially productized for Tops-20.  It seems to have started out as a local development by Robert Brown of CSSE, which was taken over by Phil Budne, who was an LCG SWS and thus given a certain amount of internal DEC support. It's got a number of issues, which I've rewritten up for later, but nothing that would defeat its usage.  Basically, it's crying out to be brought up to Tops-20 7.1 standards and would significantly benefit in other areas, the first being debugging and the second being maintainability.  Debugging is always a challenge for multi-forking software, which--to a certain extent--has to be designed to be debugged.  Indeed, I've stumbled over bugs in DDT exactly because I was messing around with such multi-forking programs as FAL and the mail system. I hasten to repeat (or re-paraphrase, if you will) what I've said in the past: it's hardly fair to criticize software some thirty years after the fact, especially when it has had no champion or maven in all that time.  And, I don't like doing that in any case when nobody is around to answer questions, particularly the original designers or authors. For now, I've put this aside and continue to concentrate on arriving at a release candidate for PANDA II.  I'll send a brief update on the current status later.