I am trying to understand how Asterisk handles an INVITE that does not contain an OFFER (i.e., the SDP body is NULL), to enable a third-party click-to-call functionality (just to provide you a brief overview of the intended application).
Network capturing (done using Wireshark) seemed to indicate that even without an explicitly defined OFFER in the initial INVITE, the SDP body contains default media codecs (specifically, for audio and video). In this context, I was wondering if Asterisk automatically assigns these default media codecs when the OFFER is empty? Further, would it be possible to change this default behavior (i.e., to maintain NULL in the SDP offer).
PS. Will post more information should you need them