From 55b02c924f696751a6fb2ee81568a1cace8d445b Mon Sep 17 00:00:00 2001
From: Dave Horton <daveh@beachdognet.com>
Date: Tue, 3 Aug 2021 10:41:19 -0400
Subject: [PATCH] if we get re-invite with no SDP (looking at you, BT) just
 respond with current offer

---
 lib/call-session.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/call-session.js b/lib/call-session.js
index 4f08e3a..c54fc8d 100644
--- a/lib/call-session.js
+++ b/lib/call-session.js
@@ -265,6 +265,12 @@ class CallSession extends Emitter {
 
   async _onReinvite(dlg, req, res) {
     try {
+      /* check for re-invite with no SDP -- seen that from BT when they provide UUI info */
+      if (!req.body) {
+        this.logger.info('got a reINVITE with no SDP; just respond with our current offer');
+        res.send(200, {body: dlg.local.sdp});
+        return;
+      }
       const fromTag = dlg.type === 'uas' ? this.rtpEngineOpts.uas.tag : this.rtpEngineOpts.uac.tag;
       const toTag = dlg.type === 'uas' ? this.rtpEngineOpts.uac.tag : this.rtpEngineOpts.uas.tag;
       const offerMedia = dlg.type === 'uas' ? this.rtpEngineOpts.uac.mediaOpts : this.rtpEngineOpts.uas.mediaOpts;