What signaling protocol is supported by IBM Sametime for audio/video sessions? 06/12/2017 – by Mod_GuideK 0 What signaling protocol is supported by IBM Sametime for audio/video sessions? A. SIP B. PSTN C. H.239 D. H.323 SHOW ANSWERSCorrect Answer: A Explanation/Reference: Download Printable PDF. VALID exam to help you PASS.