I am using Asterisk 18.2.2. When I call from one extension to another, the INVITE that Asterisk is sending to the called extension is not including any SDP at all:
<--- Transmitting SIP request (1156 bytes) to TCP:10.75.22.212:37334 --->
INVITE sip:my_sip_account@10.75.22.212:37334;transport=tcp;pn-type=firebase;app-id=[redacted];pn-tok=[redacted];pn-timeout=0;pn-silent=1 SIP/2.0
Via: SIP/2.0/TCP 10.75.22.8:5060;rport;branch=z9hG4bKPj1fa40ba5-8fec-4db3-bcf4-b7720f73678a;alias
From: "[redacted]" <sip:[redacted]@10.75.22.8>;tag=e9c5b70a-8444-45f6-ad2c-2f0a06a1ec80
To: <sip:my_sip_account@10.75.22.212;pn-type=firebase;app-id=[redacted];pn-tok=[redacted];pn-timeout=0;pn-silent=1>
Contact: <sip:asterisk@10.75.22.8:5060;transport=TCP>
Call-ID: 265bf877-b221-45e2-b7b9-33d4193bc027
CSeq: 29228 INVITE
Allow: OPTIONS, REGISTER, SUBSCRIBE, NOTIFY, PUBLISH, INVITE, ACK, BYE, CANCEL, UPDATE, PRACK, MESSAGE, REFER
Supported: 100rel, timer, replaces, norefersub, histinfo
Session-Expires: 1800
Min-SE: 90
Max-Forwards: 70
User-Agent: Asterisk PBX 18.2.2
Content-Length: 0
<--- Received SIP response (566 bytes) from TCP:10.75.22.212:37334 --->
SIP/2.0 100 Trying
Via: SIP/2.0/TCP 10.75.22.8:5060;rport;branch=z9hG4bKPj1fa40ba5-8fec-4db3-bcf4-b7720f73678a;alias
From: "[redacted]" <sip:[redacted]@10.75.22.8>;tag=e9c5b70a-8444-45f6-ad2c-2f0a06a1ec80
To: <sip:my_sip_account@10.75.22.212;pn-type=firebase;app-id==[redacted];pn-tok==[redacted];pn-timeout=0;pn-silent=1>
Call-ID: 265bf877-b221-45e2-b7b9-33d4193bc027
CSeq: 29228 INVITE
Content-Length: 0
The call ends up being terminated immediately upon answer by the caller with:
[May 20 05:31:00] ERROR[4901]: res_pjsip_session.c:902 handle_incoming_sdp: PJSIP/my_sip_account-00000012: Couldn't negotiate stream 0:audio-0:audio:sendrecv (ulaw|opus|codec2|g723|alaw|gsm|g726|g726aal2|adpcm|slin|slin12|slin16|slin24|slin32|slin44|slin48|slin96|slin192|lpc10|g729|speex|speex16|speex32|ilbc|g722|siren7|siren14|testlaw|g719|silk8|silk12|silk16|silk24)
Ultimately the above error and the call terminating are the symptom I am trying to resolve, but the INVITE without an SDP seems suspicious. Is it related?