On Tue, 01 Dec 2020 22:46:28 +0100, Michael Logies wrote:

But there seem to be different flavors of IPP, "IPP Everywhere" being
the newest one.
Have you tested this one?
https://play.google.com/store/apps/d...&hl=de& gl=US
CUPS Printing

Hi Michael Logies,
Thanks for that warning that CUPS' IPP may have different flavors, where, I
claim I've tried _ever_ free CUPS "print service" on both F-Droid & Google
Play.

Only belatedly have I realized they will _never_ work simply because all
require a "CUPS Server" (not to be confused with Android "Print Services".

Other ways:
https://www.xda-developers.com/andro...t-service-ipp/
Android Oreo Introduces Built-in Print Service for Printers that
Support the IPP

As far as I can tell, IPP won't work without a "print server" (not to be
confused with an Android "print service"), such as a CUPS print server.

I'm only slowly realizing the "Print Service" simply means that apps can
use the Android API to talk to that Print Service via the "File Print" of
that Android app. The Android "Print Service" doesn't seem to do much else.

I had read that very same article a while ago, where it's one reason I said
all the Mopria apps were, essentially, scams, as the default Android "Print
Service" is Mopria certified.

Given my HP LaserJet 2100tn Ethernet'd printer is _not_ Mopria certified
o Mopria-certified HP Printers
https://support.hp.com/us-en/document/c04459315
"In Windows 10, printing is automatically enabled when the Windows 10
update has been applied (effective October 2018). In Android, you can
print to Mopria-certified printers using the Default Print Service app
built in to Android 8.0 and newer devices."

There's no way the default Android "print service" is gonna work for me:
https://mopria.org/certified-products

The only way (AFAICT) the defulat "print service" can work is via IPP,
which, again, I think requires a _separate_ CUPS (or other) Linux-based
"print server" (not to be confused with Android "print services").

The Android "print service" merely energizes the "File Print" menu in
Android apps (AFAICT), & doesn't actually add much more value than that.

(...)
If you have an older printer that does not support the IPP, though,
then you will still need to install the app recommended by the
PrintRecommendationService,
https://android.googlesource.com/pla...dationService/.
You can learn more about this from a Google I/O 2016 presentation
here,
https://www.youtube.com/watch?v=M_JG...tu.be&t=16m20s
(...)

My HP LaserJet 2100tn Ethernet'd printer appears to support IPP based on a
network scan I ran from Android this morning showing 631 as an open port:
o https://i.postimg.cc/L4YqhR1P/printing16.jpg

However, I'm slowly coming to the realization that nothing will work using
port 631 (CUPS defaults to IPP) until/unless I add a CUPS print server.

It's trivial to find a step-by-step tutorial to set up a Linux CUPS server:
o Set Up CUPS Print Server on Ubuntu (Bonjour, IPP, Samba, AirPrint)
https://www.linuxbabe.com/ubuntu/set-up-cups-print-server-ubuntu-bonjour-ipp-samba-airprint

But there are no tutorials (AFAICT) for setting up a Windows CUPS server.
o If they exist, & I just haven't found them, I'd love a pointer to one!

In summary, as far as I can tell (and I may very well be wrong), there is
no chance for the Mopria/CUPS/IPP default Print Service to work on Android
with my Ethernet's printer without a Linux CUPS server on my network.

Given there's almost zero change of setting up a Windows CUPS server, the
only way Windows 10 can help, I think, is via some kind of "shared" setup.

Otherwise, the only solution on the planet, known to me anyway, is the one
I came up with by help from people like you, and determined trial & error.
--
Some problems are harder to resolve because the industry went to the cloud.