"Poor man's routing" as it appears in DECnet means a way to communicate with nodes that are unreachable by the primary protocol mechanisms. It works by making the user specify an explicit path to the destination (shades of uucp mail). For example, mail might be addressed to VAX4::STAR::Goldstein, i.e., the recipient was on node STAR but to get there I'd have to use VAX4 as an intermediate point. In Phase II, PMR would be used to reach destinations more than one hop away. With a mix of Phase III and IV, the Phase III nodes would need PMR to reach out of area destinations. And when "hidden areas" were used to deal with topologies that needed more than 63 areas -- such as DEC's internal network -- PMR would be used to get into or out of a hidden area. PMR the concept might be implemented in a number of different ways. Some applications, like MAIL, would provide it as part of the application. File transfer (DAP protocol) would offer it as a side effect of VMS transparent network access. And some applications, I think the old network terminal protocols might be an example, would rely on a separate application layer forwarder program. That would be PMR or PSTHRU, object 123. PMR as a separate program might originate on TOPS-10 since it has a program by that name that also provides the equivalent service on ANF-10. Someone posted the source of that recently (a year ago or so, perhaps). I don't remember ever seeing a protocol spec for the PMR protocol. Since I have the RSTS source code (it's a program PMR.BAS, in Basic-PLUS) I can reverse engineer such a spec, that's on my "soon" list. I don't remember if PMR was included with the DECnet kit. It's a pretty small and simple program. paul

On 2021-12-28 02:09, John Forecast wrote: A PMR.TSK does exist for RSX. Unless I remember wrong, it's among the "unsupported" utilities. Not sure I've seen any library function, but that might just mean I haven't looked. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

On 2021-12-28 16:23, John Forecast wrote: Oh! Nice. Thanks for the pointer. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

Your mention of PHONE rung a bell.? Err...? Jogged a memory. Tops-20 implements the VAX PHONE protocol (object 29).? The source code includes a separate file called 'DNCONN', which is a generalized implementation of PMR, meaning it can be linked with other modules.? As an aside, another pleasant memory was that I recognized the author, Larry Campbell, from my Marlboro days. The Tops-20 mail system implements just about any kind of routing you can think of, MAIL-11, SMTP, BITNET and that odd Unix 'bang' notation.? It's odd for Tops-20 people because ! is a comment character for COMND%. Version 4 and 5 Tops-20 implemented NRT connection handling and user space.? Both the NRT server and client did PMR, but predate DNCONN, so they don't use it.? For better execution, speed, the NRT server was moved into the monitor, but I believe the connections were still handled in user space.? By version 6, the connection logic was moved into the monitor as well as the client logic. The way the client logic worked is interesting; you'd make a connection and then issue an MTOPR% and the monitor would take control of the terminal, doing all the character handling in monitor mode, which eliminated a lot of context switching and (presumably) yielded better cache performance.? At Columbia, we realized that this effectively made SETHOST redundant and put the parsing code into the EXEC, thus saving us a fork slot. The only downside was that you could no longer link a DECnet connection to an NRT in user mode, which eliminated DNCONN and broke certain kinds of solutions.? It's on my list to put it back. I don't recall about the Tops-20 CTERM client.