[zaarn]

>But do they block port 853 and if so, on what grounds?

I don't know why they decide to block it but they do. Most of the time it's to prevent spam or to protect customers (ports lower than 1024 are sometimes blocked for that reason).

>They sell you an Internet access, if a port is blocked, this is no longer a valid Internet access.

That's a laughable argument, they don't sell you unrestricted internet access, that's already given by the fact we have datacaps and SMTP traffic from port 25 blocked.

Fact is, ports get blocked. The mentioned networks do it a lot. We should accomodate these restrictions because alternatively the software breaks for a consumer and if it's a choice between "uninstall DNSCrypt/DoT/DoH" or "complain to ISP or operator" then most consumers will not complain to the ISP because prior to DNSCrypt their internet worked for all they care.

[gsich]

>That's a laughable argument, they don't sell you unrestricted internet access, that's already given by the fact we have datacaps and SMTP traffic from port 25 blocked.

Some do and I would complain about it. Maybe port 25 has a spam related reason, but every other port has not.

But to come back: crappy networks are not a reason to ditch "custom" ports. Fix the network.

[zaarn]

>But to come back: crappy networks are not a reason to ditch "custom" ports. Fix the network.

I heavily disagree. Broken and crappy networks exist and for the user it's easier if the software we write works on broken and crappy networks. Most users will not complain to the network if YOUR software doesn't work on it but other software works fine.

That's simply the reality of the situation.

[gsich]

You can disagree all you want. Nothing will change if you build for crappy networks. Build your application so that it can detect such a setup and tell the user.

It works for gaming. This alone is proof that it can work.

[zaarn]

It works for gaming because most games that need non-crappy networks happen to run on connections that are more rarely crappy networks.

And despite that I get regular issues when I need to play true p2p lobby games because of various people having a variety of difficult-to-work-around routers or ISPs. So in part atleast it doesn't work for gaming either. I don't consider your proof valid.

[gsich]

If you consider port 80/443 as essential, then you can add 853 to that list. Every network who blocks it, blocks an essential port, similar to blocking 443. This is the angle one needs to work with here. Why keep the status quo for all eternity?

People have difficulties port forwarding. It's fixable, but then again, this is a different issue. You are talking about incoming ports, not outgoing.

[zaarn]

Adding ports to a list of "essential" ports is hard considering some middleboxes haven't been updated since IPv6 standard was published (1998) and those aren't even the oldest once I've seen. They will drop and mangle packets as they please and unless it costs them millions of dollars a month these boxes will not be replaced or reconfigured, period. That is reality on the internet.