[ih] Fwd: Question - reference source for formal decommissioning of ARPANET in 1990?

[Alex McKenzie]

 Dan,
I have no direct knowledge, but I do no that at the time of the NCP -> TCP cutover there were only a couple of ARPANET sites doing classified work, and their attachment was via PLI's (Private Line Interface) built by BBN which incorporated NSA approved bit-stream encryption devices. The PLIs packetized the encrypted bit stream and appended/deleted IMP headers on the packets.  The classified hosts could just think of the ARPANET as a wire (a "private line").  After the cutover to TCP the PLIs were replaced by IPLIs (Internet Private Line Interface).
There were various ARPANET clones delivered to government agencies.  The Hosts on those networks may have never switched to TCP, but I don't know whether they even used NCP; there was little or no unclassified information available about the use of those networks.
Alex

    On Sunday, December 6, 2020, 10:53:00 AM EST, Dan Lynch via Internet-history <internet-history at elists.isoc.org> wrote:  
 
 Andy, I knew there were exceptional cases and that BBN was the watchdog. I had heard a rumor that many military sites were running classified applications on NCP and would probably never be able to use TCP. 

Dan

Cell 650-776-7313

> On Dec 5, 2020, at 8:50 AM, Andrew G. Malis <agmalis at gmail.com> wrote:
> 
> 
> Dan,
> 
> I managed the NCP->TCP transition on the ARPANET that started on 1/1/83. I wrote the IMP code that enforced the transition by adding a filter to drop NCP packets, which was managed on a host-by-host basis. We had an official list from DARPA of hosts that were approved to continue using NCP. I spent New Year's Day in the NOC, turning off NCP for unapproved hosts, and I fielded calls from unhappy site managers as their NCP traffic stopped flowing (as they had been warned many times). I told them the process of how to contact DARPA to at least temporarily get on the approved list, and I turned the filters off and back on as directed by DARPA. Sadly, I don't recall when we finished the process of turning on the NCP filter for all hosts.
> 
> Cheers,
> Andy
> 
> 
>> On Fri, Dec 4, 2020 at 7:31 PM Dan Lynch via Internet-history <internet-history at elists.isoc.org> wrote:
>> I only use real data😂🙀
>> 
>> Dan
>> 
>> Cell 650-776-7313
>> 
>> > On Dec 4, 2020, at 4:26 PM, Dave Crocker <dhc at dcrocker.net> wrote:
>> > 
>> > On 12/4/2020 4:22 PM, Dan Lynch via Internet-history wrote:
>> >> It amazes me to hear there were sites still running NCP in the late 80s in Texas.
>> > 
>> > A reference like that, about Texas, affords such a target-rich opportunity, I'm overwhelmed.
>> > 
>> > d/
>> > 
>> > -- 
>> > Dave Crocker
>> > Brandenburg InternetWorking
>> > bbiw.net
>> 
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