Tcp port number and mdns service name conventions

I like to control a Particle Photon with an app over the local network. I implemented a webserver ( but I think it’s unnecessary overhead. Just sending commands over “raw” tcp will do.

I’m curious what will be a good port and service name for this. Of course you can pick anything, but maybe there are some conventions.

I saw that Evothings used port 23 (telnet).

I’ve found myself the “raw-serial” service in the iana registry with port 2167.

Why not use the port range 49152 to 65535 which is not reservable by any Internet service and designed to be used exactly for this purpose? Reusing someone else’s ports will confuse some devices particularly if there is ever going to be any active management on the subnet like at a University or workplace. Having an open telnet port would get you shutdown at my work for sure, even if it was for an innocent purpose.


That’s a good tip. However this makes me think that it might be smarter to stick with http? Since there aren’t many companies that close port 80.

If I use a free port range, how I would publish the service on mDNS. Am I free to pick any service name?