[Simh] RTS/8 and DECnet

[John Forecast]

> On Mar 15, 2016, at 9:13 AM, Paul Koning <paulkoning at comcast.net> wrote:
> 
> 
>> On Mar 15, 2016, at 5:47 AM, Johnny Billquist <bqt at softjar.se> wrote:
>> 
>> ...
>> I don't remember who I talk to, but it might have been Paul, but it appears DECnet-8 is pretty much Phase I, from what we figured out. Maybe DEC wrote some newer version that have not been found, since documentation and SPDs mention Phase II.
> 
> I saw an RTS/8 document that describes Phase I -- studied it some to see what Phase I protocol looks like.  The answer is: significantly different from Phase II, not interoperable, no plausible way to make it interoperate.  The key problem is that the NSP details are different, so a Phase I endpoint trying to talk to a Phase II endpoint would get lost.  Compare that to Phase II through IV where the NSP is basically the same -- Phase III adds retransmission, but the packet formats are upward compatible.
> 
> But I also remember hearing about Phase II on PDP-8 systems.  So it seems likely that Phase I was created at some time, only to be superseded by a Phase II implementation.
> 
> 	paul
> 
> 

I joined the Communications group in Jan ’77. They were responsible for DECnet-8, DECnet-RT, DECnet-11M/S and DECnet-11D/IAS (all phase II at that time). Sometime around the middle of the year all of the PDP-8 developers (maybe 2) moved out and a few months later the RT developers left as well. The remaining products shipped about a year later.

All the RSX products used a common implementation of NSP to ease interoperability. A generic DECnet-8 would have been a tight squeeze and the same for DECnet-RT (not sure if mapped system support was available then), it was pretty difficult getting an unmapped DECnet-11M system configured and even worse on 11S (at least you could overlay NETACP on 11M).

  John.

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