SIP 486 Busy Here
KamailioRFC 3261 §21.4.21The endpoint is busy on another call. Distinct from 600 Busy Everywhere.
Common causes on Kamailio
- User on another call
- Single-line endpoint (no call waiting)
- Forking proxy: one branch returned 486 first
Stop guessing — paste your trace
Drop your PCAP or sngrep log and SIP Flow will render the ladder, surface the failing transaction, and (optionally) ask Gemini to suggest the fix grounded in Kamailio docs.
Open analyzerDon't have a trace yet? See how to capture one in Wireshark, sngrep, or your PBX