[HECnet] DECnet/Python

[Johnny Billquist]

To answer Brian in one way - I usually try to organize so that people 
get hooked up to someone physically close to them, who are sortof local 
HECnet access points. There are a bunch of people I have on my list that 
I tend to make use of for this, but it is otherwise pretty flexible.

But it don't make sense to have the link going to someone far away. That 
just means silly roundtrips if you then talk to someone nearby, while 
for connections far away, it's going to make that jump anyway, no matter 
where you connect.

And a few questions/comments on what Paul wrote:

On 2021-10-27 15:06, Paul Koning wrote:
> A couple of considerations:
> 
> 1. Is there a backbone router in your area?  If yes, you'd want to connect there.

With area I assume you mean physical area here, and not DECnet area.

> 2. If you want to set up an area router, you'd want to offer connections to other nodes in your area.  And you'd definitely need to connect to other area routers in your area, if there are any (to help prevent partitioned areas).
> 3. Look for potential peers with good Internet service and low latency.

Good points.

> As for connection type, I'd recommend DDCMP over TCP, DDCMP over UDP, or Multinet over TCP.  Do NOT use Multinet over UDP.  GRE works also but for wide area use it's a bit screwy because it essentially emulates a point to point Ethernet, with the datagram (unreliable) delivery and the short timers that implies.  There is also bridged Ethernet (Johnny Billquist bridge); that works but it would not be the first option I'd choose.

The main issue with my bridge is really about scalability. You don't 
really want ethernet segments with hundreds of nodes and possibly 
routers on them. Traffic grows with that, and you also have resources on 
each router which grows with the number of routers on the segment.

Another "problem" is about how to set costs if there are both nodes very 
close, and nodes very far away on the same ethernet segment.

So I also don't recommend the bridge in general, but it is sometimes 
both useful and convenient. And if you create a more local ethernet 
bridge, the problems mentioned above become smaller.

For the others, Paul pretty much summed it up. In addition, it should 
probably be mentioned that Multinet over TCP or UDP is possible inside 
VMS and RSX (as well as with PyDECnet). DDCMP over TCP or UDP is 
possible with PyDECnet (actually, I could probably add that in RSX as 
well), while GRE is mainly for Cisco, but I think PyDECnet also can do 
that one?

So choices are somewhat dependent on what system/software you are using.

   Johnny

> 
> 	paul
> 
>> On Oct 27, 2021, at 4:08 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
>>
>> On the subject of PyDECnet If I were to stand it up how/who should I be connected to?
>>
>> -brian
>>
>>
>>
>> On 26/10/21 12:57, fsword007 at gmail.com wrote:
>>> Folks,
>>>   
>>> I successfully installed DECnet/Python on Ubuntu 21.10 system and was successfully connected to HECnet.
>>>   
>>> I have a few questions about DECnet/Python.  I choose that because it support virtual circuits like Multinet over TCP,  etc..
>>>   
>>> I can’t find any apps (programs) to support DECnet/Python like login, set host, dir, etc.  Only DECnet for Linux has programs.
>>>   
>>> Does DECnet for Raspberry Pi work with Ubuntu 21.10 (Linux 5.13 for x86)?
>>>   
>>> Tim
> 

-- 
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