Registered to XRL; effectively unused in the wild, so an open 1104 is something else entirely.
IANA assigns 1104 to a service named xrl for both TCP and UDP, with no public protocol specification behind the registration. Nmap's frequency data records it as open on a vanishingly small fraction of scanned hosts. Treat an open 1104 as an unidentified local application that grabbed a low free port, not as evidence of XRL.
Expose with care
Nothing standard listens here, so the first job is identifying the process; do not expose a service you cannot name.
$ sudo lsof -nP -iTCP:1104 -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.