[HECnet] DECnet-10 doesn't work past Nov 9 2021?

[Johnny Billquist]

On 2020-12-27 18:30, John Forecast wrote:
> 
>> On Dec 27, 2020, at 11:46 AM, Robert Armstrong <bob at jfcl.com 
>> <mailto:bob at jfcl.com>> wrote:
>>
>>   This topic came up on the alt.sys.pdp10 list
>> https://groups.google.com/g/alt.sys.pdp10/c/ZttQxHZGEJQ 
>> <https://groups.google.com/g/alt.sys.pdp10/c/ZttQxHZGEJQ>
>> Apparently DECnet-10 won’t work past November 9^th 2021, which isn’t 
>> that far away.   Personally I’d never heard this before and had no 
>> idea, and since I know there are a few 36 bit emulations on HECnet 
>> that are obviously using DECnet I thought I’d pass it along.
>>   TOPS20 isn’t explicitly mentioned, but I’m guessing that it has the 
>> exact same issue.  That’d mean no DECnet on 36 bit systems after next 
>> year!  Unless, of course, you want to start playing games with the 
>> date (which I hate doing)…
>> Bob
> 
> It’s not just a DECnet-10/20 problem. DECnet event logging for any 
> system may fail after Nov 9th 2021. Events are time-stamped when they 
> are generated with a 2-byte field holding the number of half julian days 
> since Jan-1 1977. The spec (Network Management 4.0.0, page 170/171) 
> implies that these 2 bytes should be treated as a signed value (0 - 
> 32767) which will overflow on Nov 9th 2021. If the code treats it as 
> unsigned, then we’re good for another 44 years. I wrote most of the RSX 
> and Ultrix event logging code but I don’t remember if that field was 
> treated as signed or unsigned. Phase V fixed the problem allowing the 
> time stamp to go well past the year 9999.

This is explicitly mentioned in the RSX-11M-PLUS V4.6 release notes. 
Section 8.8.

8.8.1 is about DAP, which specifies dates in ASCII, using DDMMMYY. RSX 
will treat YY 70-99 as in the 20th century, and 00-69 as in the 21st 
century.

8.8.2 is about Network Management Protocol V4.2.0, where it is 
explicitly stated that RSX will treat that number as unsigned, and will 
work until 2065. After that, it will roll around. Logging will still 
work, but dates will be back to 1977 in the logs.

   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