Subject: Re: ACK packets?

From: John Goerzen <[email-masked]>
Date: Sun, 14 Dec 2025 23:41:13 -0600

On Sun, Dec 14 2025, Hadmut Danisch wrote:

> Am 14.12.25 um 01:11 schrieb John Goerzen:
>> You
>> could also use them if you think that, for instance, machine B in your
>> example is not entirely reliable.
>
>
> That's what I had intended, but when using internet connections instead of
> usb-drives, I'm not using nncp-xfer, but nncp-exec, nncp-file, nncp-daemon, and
> nncp-caller, and as far as I can see, they do not support this -keep option.

Hi Hadmut,

It sounds like you might be confusing the different types of commands.
exec and file both create packets.  daemon and caller exchange them over
the network, and of course xfer exchanges them over the filesystem.

-keep wouldn't be relevant for exec or file, since they don't do
anything that would remove packets.
https://www.complete.org/nncp-concepts/ may possibly help you out there.

The network protocol confirms delivery to the next hop itself, so
packets are only deleted off the origin machine with daemon or caller
once the remote confirms delivery.

However, this of course can't protect against an intermediate maching
dying in the midst of a multihop delivery.  I could see ack being useful
there.  Sergey will have to comment on that one.

- John