{
  "port": 1863,
  "protocol": "tcp",
  "service": "MSNP (MSN Messenger Protocol)",
  "oneLiner": "MSN/Windows Live Messenger's chat protocol — the service is dead, but the port number long outlived it.",
  "whatItIs": "IANA registers 1863 as \"msnp\" for Microsoft, the notification-server port for MSN Messenger and its successor Windows Live Messenger: clients connected here for sign-in, presence, contact lists, and switchboard sessions. Microsoft never published a specification, and the service was retired worldwide in 2013 in favour of Skype, with the China holdout closing in 2014. What kept 1863 alive afterwards is habit — third-party IM software, bots, and proxies that grew up around MSNP kept using the number, and some unrelated services picked it for being memorable.",
  "exposure": {
    "verdict": "careful",
    "note": "No legitimate Microsoft service listens here any more, so an open 1863 is some other program that happened to take the port — identify it rather than trusting the name."
  },
  "checkCommand": "nc -vz -w 3 TARGET 1863",
  "links": [
    {
      "title": "IANA port registry — 1863 (msnp)",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1863",
      "kind": "iana"
    }
  ]
}