{
  "room": "read-a-ladder",
  "checked": "2026-10",
  "sources": [
    {
      "kind": "rfc",
      "title": "RFC 3261, SIP",
      "url": "https://www.rfc-editor.org/rfc/rfc3261",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "rfc",
      "title": "RFC 3515, SIP REFER",
      "url": "https://www.rfc-editor.org/rfc/rfc3515",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "rfc",
      "title": "RFC 3264, offer/answer",
      "url": "https://www.rfc-editor.org/rfc/rfc3264",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "rfc",
      "title": "RFC 3550, RTP",
      "url": "https://www.rfc-editor.org/rfc/rfc3550",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "cisco",
      "title": "Cisco Unified Border Element product support",
      "url": "https://www.cisco.com/c/en/us/support/unified-communications/unified-border-element/series.html",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "cisco",
      "title": "Understand IOS and IOS XE call routing",
      "url": "https://www.cisco.com/c/en/us/support/docs/voice/ip-telephony-voice-over-ip-voip/211306-In-Depth-Explanation-of-Cisco-IOS-and-IO.html",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "community",
      "title": "Cisco Community, Collaboration knowledge base",
      "url": "https://community.cisco.com/t5/collaboration-knowledge-base/tkb-p/4691-docs-collaboration-voice-video",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    },
    {
      "kind": "wikipedia",
      "title": "Session Initiation Protocol (Wikipedia)",
      "url": "https://en.wikipedia.org/wiki/Session_Initiation_Protocol",
      "status": "verified",
      "last_checked": "2026-10",
      "note": ""
    }
  ]
}