Hello, I have a strange phenomen: When a target UA is busy, it returns "486 Busy" to Freeswitch. But Freeswitch then returns "480 Temporarily Unavailable" to the called party. Where does this come from and how can I change this behaviour? See (anonymized) SIP trace with ngrep: UA to Freeswitch: ======================== U 2012/01/04 13:59:44.928775 <fritzbox-IP>:5060 -> <freeswitch-IP>:5080 SIP/2.0 486 Busy Here. Via: SIP/2.0/UDP <freeswitch-IP>:5080;rport=5080;branch=z9hG4bKNZZDv0Syp4eyr. From: "026xxxxxxxx" <sip:026xxxxxxxx@<freeswitch-IP>>;tag=py094Kv7vr03a. To: <sip:069xxxxxxxx@<fritzbox-IP>;uniq=B05FE4881A55AEEB69361EFA327DB>;tag=E1C3374B97DAB2DE. Call-ID: d0d0d057-b176-122f-1f8d-001ec9b9da3c. CSeq: 22504928 INVITE. User-Agent: AVM FRITZ!Box 6360 Cable 85.05.07 (Sep 14 2011). Content-Length: 0. Freeswitch to Caller: ======================== U 2012/01/04 13:59:44.930387 <freeswitch-IP>:5060 -> <Sip-provider-IP>:5060 SIP/2.0 480 Temporarily Unavailable. Via: SIP/2.0/UDP <Sip-provider-IP>:5060;branch=z9hG4bK-4896-2830DFA. From: <sip:4926xxxxxxxx@sip.provider.de;user=phone>;tag=13517-HB-08a98588-2622da197. To: <sip:4969xxxxxxxx@<freeswitch-IP>;user=phone>;tag=XQtc5US24QgDa. Call-ID: 13517-SG-08a98587-0a352e121@sip.provider.de. CSeq: 134781549 INVITE. User-Agent: FreeSWITCH-mod_sofia/1.0.head-git-68627e8 2011-11-21 13-52-28 -0600. Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, UPDATE, INFO, REGISTER, REFER, NOTIFY. Supported: precondition, path, replaces. Allow-Events: talk, hold, refer. Content-Length: 0. P-Asserted-Identity: "069xxxxxxxx" <sip:069xxxxxxxx@<freeswitch-IP>>. Best regards Peter