From a99db56449f1797186ce14597ac565d0bd4e94a4 Mon Sep 17 00:00:00 2001
From: Hoan HL <hoan.h.luu@drachtio.org>
Date: Wed, 1 Jul 2026 14:55:34 +0700
Subject: [PATCH] wip

---
 data/srtp-transcoding.json |  2 +-
 lib/call-session.js        | 40 --------------------------------------
 2 files changed, 1 insertion(+), 41 deletions(-)

diff --git a/data/srtp-transcoding.json b/data/srtp-transcoding.json
index e6182f3..5bc99d9 100644
--- a/data/srtp-transcoding.json
+++ b/data/srtp-transcoding.json
@@ -4,7 +4,7 @@
     "ICE": "force",
     "SDES": "off",
     "flags": ["generate mid", "SDES-no", "port latching"],
-    "rtcp-mux": ["require"]  
+    "rtcp-mux": ["offer"]
   },
   "teams": {
     "transport-protocol": "RTP/SAVP",
diff --git a/lib/call-session.js b/lib/call-session.js
index 9d39f85..cd41398 100644
--- a/lib/call-session.js
+++ b/lib/call-session.js
@@ -549,46 +549,6 @@ class CallSession extends Emitter {
             localSdpA: async(sdp, res) => {
               this.rtpEngineOpts.uac.tag = res.getParsedHeader('To').params.tag;
 
-              /* HACK (rtcp-mux): some far ends answer an m-line WITHOUT a=rtcp-mux even though
-                 we offered it, advertising a separate RTCP port + a 2nd ICE component they never
-                 service. That dead RTCP component blocks ICE completion and therefore DTLS on that
-                 stream (no SRTP keys -> "no crypto suite negotiated", no audio). Force rtcp-mux back
-                 on every audio m-line and drop the standalone a=rtcp port / component-2 candidates
-                 so rtpengine keeps a single muxed component. */
-              const forceRtcpMux = (sdpStr) => {
-                if (!sdpStr || !sdpStr.includes('m=')) return sdpStr;
-                const eol = sdpStr.includes('\r\n') ? '\r\n' : '\n';
-                const lines = sdpStr.split(/\r?\n/);
-                const result = [];
-                let section = [];
-                let isAudio = false;
-                const flush = () => {
-                  if (!section.length) return;
-                  if (isAudio) {
-                    const hasMux = section.some((l) => l.startsWith('a=rtcp-mux'));
-                    let kept = section.filter((l) => {
-                      if (/^a=rtcp:\d+/.test(l)) return false;            // separate RTCP port
-                      const m = /^a=candidate:\S+\s+(\d+)\s+/.exec(l);     // component 2 == RTCP
-                      if (m && m[1] === '2') return false;
-                      return true;
-                    });
-                    if (!hasMux) kept = [kept[0], 'a=rtcp-mux', ...kept.slice(1)];
-                    result.push(...kept);
-                  } else {
-                    result.push(...section);
-                  }
-                  section = [];
-                };
-                for (const l of lines) {
-                  if (l.startsWith('m=')) { flush(); section = [l]; isAudio = l.startsWith('m=audio'); }
-                  else if (section.length) section.push(l);
-                  else result.push(l);
-                }
-                flush();
-                return result.join(eol);
-              };
-              sdp = forceRtcpMux(sdp);
-
               const opts = {
                 ...this.rtpEngineOpts.common,
                 ...this.rtpEngineOpts.uas.mediaOpts,