The list of UDP ports at Wikipedia(1) doesn't show port 93 or 10093, so I suggest we correct Wikipedia's list, since port 93 is shown as assigned to "Device Control Protocol" by the IANA(3).
Yes, our usage of port 93/UDP for AXUDP is completely unrecognized by IANA. There is no official document describing AXUDP so there is no way for us to claim a port - although there's no prohibition on using any port number we want, since port numbers are not absolutes. Still, it's not wise to double-up on port numbers.
In general, high numbered ports like 10093 are up for grabs, so we can continue to use it unless someone bigger comes along and claims it. If someone writes up a protocol description of AXUDP, we can publish that document and then use it as justification for claiming 10093. That would give us a reference for inclusion of port 10093 in Wikipedia's list.
I don't know how many implementations of AXUDP are hard-coded to use port 93, nor how many host pairs are using it that would have to change if we made 10093 'official' in some way. Something might break.
I don't know if we can apply for something like port 114, so please tell me if a "System" port number would be appropriate for AX.25-over-UDP, and if a new IP protocol number is needed. TIA.
I don't think we need a well-known 'system' port number (ie, 1023 and lower) because all AXUDP connections are by agreement. All we need is a port that's unlikely to be used for anything else.
No, a new IP protocol number isn't needed, since it's using UDP (which is IP protocol 17), not raw IP, for transport. - Brian