[Info-vax] Reading Gordon Bell's VAX strategy document

[Dan Cross]

In article <uf4s1t$cle$6 at news.misty.com>,
Johnny Billquist  <bqt at softjar.se> wrote:
>On 2023-09-28 21:49, Lars Brinkhoff wrote:
>> Johnny Billquist wrote:
>>> There were of course development, and testing done between machines
>>> and so on. But that was not "ARPANET". ARPANET was running NCP until
>>> flag day, when it officially switched to IP.
>> 
>> NCP and TCP operated in parallel on the ARPANET for a while.  The
>> Internet Protocol Transition Workbook from November 1981 encouraged new
>> hosts to only implement TCP, not NCP, and says at that point there were
>> TCP-only hosts.  On several occasions during 1982, NCP was temporarily
>> blocked, but TCP was allowed.  What happened on flag day was that NCP
>> was permanently blocked.
>> 
>> So what I was wondering was: were there any VAXen talking NCP, or did
>> they jump straight to TCP?  I'd like to see evidence, not handwaving.
>
>How would they interoperate? TCP and NCP are not exactly compatible in 
>any way.
>
>You would basically have to have two different parallel networks, and 
>them you might have some machines that would act as gateway between the 
>two networks.

Well, the statement was that they existed in parallel, not that
they necessarily inter-operated.  But communication between them
was documented in the transition guide, and there were gateways
for a while.  I even see some evidence in early sendmail
configurations that there were provisions for sending mail to
NCP gateways (e.g., `usr.lib/sendmail/cf/ncphosts.m4` in 4.1c
BSD; UDEL was the NCP gateway and the file has a comment at the
top that says, "When NCP goes away, so should this file").

	- Dan C.