Send SIP re-INVITE without SDP

[dimitros]

From what i read a re-invite can be sent without SDP but not in all cases. How can i find which are those cases?
More specific, i want to know if re-invites that are followed up with a 488 or a 491 response are supposed to send SDP.

[Joshua26]

To determine which cases a re-invitation can be sent without SDP, you will need to refer to the SIP protocol documentation and consider specific cases, especially for responses such as 488 or 491. Santo handles can use SDP included or excluded based on call flow, other connection requirements, or response format . Looking at the call signaling log will help clarify when SDP should be added.