App calls (iOS and Android) rejected with [CM503013]: Call(C:11): Incoming call rejected, caller is unknown;

[sakkask]

3CX 18.0 (Build 35) self hosted Debian / Android App 20.3.0.27 / iOS latest

Past few weeks our normally OK working mobile apps have started to be unable to place calls. registration works OK but calls made are being rejected.

Affects multiple extensions, re-registering, re-installing app does not make a difference.

Although exact timeline was not verifiable somewhere around that time we added an SBC to test something for down the line, but that does not appear to be involved. Removing the SBC does not change this behaviour.

Here is an example from our Activity Log:


03/24/2025 10:09:51 AM - [CM502001]: Source info: From: "xxxxxx"<sip:[email protected]>;tag=3898a91c-3801-4a9f-91fc-feb98968c9b9; To: <sip:008@externalIP_blanked;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7>
03/24/2025 10:09:51 AM - [CM503013]: Call(C:11): Incoming call rejected, caller is unknown; msg=Invite-IN Recv Req INVITE from 127.0.0.1:5080 tid=Pj7a190d3d-5bb5-491e-b2b1-3fe14d0e8459 Call-ID=6f5da10e-e57a-4119-86d3-0d7d045b06a4:
INVITE sip:[email protected]:5060;transport=UDP;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7 SIP/2.0
Via: SIP/2.0/UDP 127.0.0.1:5080;branch=z9hG4bK-524287-2---Pj7a190d3d-5bb5-491e-b2b1-3fe14d0e8459;rport=5080
Via: SIP/2.0/UDP UnknowPublickIP_blanked_maybe_3cx_owned:44364;branch=z9hG4bK-524287-1---tunneltid;rport;tnlid=clnt.0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0_6551240
Via: SIP/2.0/TCP 127.0.0.1:50195;rport;branch=z9hG4bKPj7a190d3d-5bb5-491e-b2b1-3fe14d0e8459;alias
Max-Forwards: 69
Record-Route: <sip:[email protected]:5080;user=proxy;uri=clnt.0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0_6551240>
Contact: "xxxxxxx" <sip:[email protected]:5060;rinstance=0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0>
To: <sip:008@externalIP_blanked;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7>
From: "xxxxxxx"<sip:[email protected]>;tag=3898a91c-3801-4a9f-91fc-feb98968c9b9
Call-ID: 6f5da10e-e57a-4119-86d3-0d7d045b06a4
CSeq: 27989 INVITE
Session-Expires: 1800
Min-SE: 90
Allow: PRACK, INVITE, ACK, BYE, CANCEL, UPDATE, INFO, SUBSCRIBE, NOTIFY, REFER, MESSAGE, OPTIONS
Content-Type: application/sdp
Proxy-Authorization: Digest username="04HsHoMuaP",realm="3CXPhoneSystem",nonce="414d535967e1134f39:e8811968b3f0d9e810ad6d9687ad9fc1",uri="sip:008@externalIP_blanked;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7",response="22deb014b9570d4a8a1a7089064c64b3",algorithm=MD5
Supported: replaces, 100rel, timer, norefersub
User-Agent: 3CXPhone for Android 20.3.0.27
Content-Length: 438

v=0
o=- 3951792592 3951792592 IN IP4 SIP_provider_IP_blanked
s=pjmedia
b=AS:117
t=0 0
a=X-nat:0
m=audio 10000 RTP/AVP 18 9 0 8 120 96
c=IN IP4 SIP_provider_IP_blanked
b=TIAS:96000
b=AS:117
a=rtcp:10001
a=sendrecv
a=rtpmap:18 G729/8000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:120 opus/48000/2
a=fmtp:120 useinbandfec=1
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
m=video 0 RTP/AVP 31
c=IN IP4 127.0.0.1
03/24/2025 10:09:51 AM - Leg L:11.1[Unknown:] is terminated: Cause: BYE from PBX
03/24/2025 10:09:51 AM - [CM500002]: Unidentified incoming call. Review INVITE and adjust source identification:
Invite-UNK Recv Req INVITE from 127.0.0.1:5080 tid=Pje7f9267d-4200-41b9-bc2b-bacbf7e9a55c Call-ID=6f5da10e-e57a-4119-86d3-0d7d045b06a4:
INVITE sip:[email protected]:5060;transport=UDP;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7 SIP/2.0
Via: SIP/2.0/UDP 127.0.0.1:5080;branch=z9hG4bK-524287-2---Pje7f9267d-4200-41b9-bc2b-bacbf7e9a55c;rport=5080
Via: SIP/2.0/UDP UnknowPublickIP_blanked_maybe_3cx_owned:44364;branch=z9hG4bK-524287-1---tunneltid;rport;tnlid=clnt.0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0_6551240
Via: SIP/2.0/TCP 127.0.0.1:50195;rport;branch=z9hG4bKPje7f9267d-4200-41b9-bc2b-bacbf7e9a55c;alias
Max-Forwards: 69
Record-Route: <sip:[email protected]:5080;user=proxy;uri=clnt.0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0_6551240>
Contact: "xxxxxx"<sip:[email protected]:5060;rinstance=0-2a52228b-fbdb-4d80-99e7-c1d94f1f71c0>
To: <sip:008@externalIP_blanked;tag3cx=e39e40a9-56a6-4f29-aedd-334678395ed7>
From: "xxxxxxxx" <sip:[email protected]>;tag=3898a91c-3801-4a9f-91fc-feb98968c9b9
Call-ID: 6f5da10e-e57a-4119-86d3-0d7d045b06a4
CSeq: 27988 INVITE
Session-Expires: 1800
Min-SE: 90
Allow: PRACK, INVITE, ACK, BYE, CANCEL, UPDATE, INFO, SUBSCRIBE, NOTIFY, REFER, MESSAGE, OPTIONS
Content-Type: application/sdp
Supported: replaces, 100rel, timer, norefersub
User-Agent: 3CXPhone for Android 20.3.0.27
Content-Length: 438

v=0
o=- 3951792592 3951792592 IN IP4 SIP_provider_IP_blanked
s=pjmedia
b=AS:117
t=0 0
a=X-nat:0
m=audio 10000 RTP/AVP 18 9 0 8 120 96
c=IN IP4 SIP_provider_IP_blanked
b=TIAS:96000
b=AS:117
a=rtcp:10001
a=sendrecv
a=rtpmap:18 G729/8000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:120 opus/48000/2
a=fmtp:120 useinbandfec=1
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
m=video 0 RTP/AVP 31
c=IN IP4 127.0.0.1

 

[xcobean]

so this happens when the call hit the phone or just disconnect at the PBX level ?

 

[sakkask]

so this happens when the call hit the phone or just disconnect at the PBX level ?

We have since upgraded to V20 which has resolved the issue. It appears the latest app versions have some degree of incompatibility with V18. I do not have older captures to pinpoint the exact change but my inclination is that the FROM/TO headers are presented has changed.