[ih] Design choices in SMTP

[Dave Crocker]

On 2/7/2023 9:44 AM, Johan Helsingius via Internet-history wrote:
> On 07/02/2023 18:39, Dave Crocker via Internet-history wrote:
>
>> Looking for a cheap way to do better, I modified his code to allow 2 
>> outstanding packets rather than one.  The result was that the modem 
>> transmit light was pinned on, with no loss of reliability or 
>> functionality.
>
> I experiences something similar - I implemented an outstanding
> packet window in the archaic but popular Kermit protocol used
> over serial lines, and boy did it improve performance.

Indeed.  And since you've played with a phone-based link-level protocol, 
I'll mention that the unusual bit of Szurkowski['s phonenet protocol was 
that it was adaptable to the details of the remote site.

When coming in through the user-oriented terminal interface, every 
system had/has special characters that are treated semantically.  
Enter/Return (CR) is an obvious example.

At initial connection, Ed's protocol had a called site send a list of 
its interpreted characters, so the caller wouldn't use them as data.  
The goal was to give the caller the widest array of characters that 
could be sent as-is, without needed to recast them in hex, or the like. 
(I don't remember which of the usual schemes he used.)

d/

d/


-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net
mast:@dcrocker at mastodon.social