No IANA assignment on TCP or UDP; nothing standard listens here.
IANA has no service registered on 9815 in either transport. Nmap's service database lists it as unknown on both TCP and UDP at low frequency, which reflects occasional application use rather than any particular product. There is no protocol document to consult and no notable security folklore attached to the number.
Expose with care
Unidentified service. Establish what it is locally, then decide — the port number carries no information either way.
$ sudo lsof -nP -iTCP:9815 -sTCP:LISTENSeen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
Get Beige Box →also available as JSON · Markdown
Corrections or a missing port? Reply @rimrocksystems.