--- a/dom/media/webrtc/WebrtcGlobal.h
+++ b/dom/media/webrtc/WebrtcGlobal.h
@@ -75,16 +75,17 @@ struct ParamTraits<mozilla::dom::RTCStat
     WriteParam(aMsg, aParam.mOutboundRTPStreamStats);
     WriteParam(aMsg, aParam.mPcid);
     WriteParam(aMsg, aParam.mRemoteSdp);
     WriteParam(aMsg, aParam.mTimestamp);
     WriteParam(aMsg, aParam.mIceRestarts);
     WriteParam(aMsg, aParam.mIceRollbacks);
     WriteParam(aMsg, aParam.mTransportStats);
     WriteParam(aMsg, aParam.mRtpContributingSourceStats);
+    WriteParam(aMsg, aParam.mOfferer);
   }
 
   static bool Read(const Message* aMsg, PickleIterator* aIter, paramType* aResult)
   {
     if (!ReadParam(aMsg, aIter, &(aResult->mClosed)) ||
         !ReadParam(aMsg, aIter, &(aResult->mCodecStats)) ||
         !ReadParam(aMsg, aIter, &(aResult->mIceCandidatePairStats)) ||
         !ReadParam(aMsg, aIter, &(aResult->mIceCandidateStats)) ||
@@ -95,17 +96,18 @@ struct ParamTraits<mozilla::dom::RTCStat
         !ReadParam(aMsg, aIter, &(aResult->mMediaStreamTrackStats)) ||
         !ReadParam(aMsg, aIter, &(aResult->mOutboundRTPStreamStats)) ||
         !ReadParam(aMsg, aIter, &(aResult->mPcid)) ||
         !ReadParam(aMsg, aIter, &(aResult->mRemoteSdp)) ||
         !ReadParam(aMsg, aIter, &(aResult->mTimestamp)) ||
         !ReadParam(aMsg, aIter, &(aResult->mIceRestarts)) ||
         !ReadParam(aMsg, aIter, &(aResult->mIceRollbacks)) ||
         !ReadParam(aMsg, aIter, &(aResult->mTransportStats)) ||
-        !ReadParam(aMsg, aIter, &(aResult->mRtpContributingSourceStats))) {
+        !ReadParam(aMsg, aIter, &(aResult->mRtpContributingSourceStats)) ||
+        !ReadParam(aMsg, aIter, &(aResult->mOfferer))) {
       return false;
     }
 
     return true;
   }
 };
 
 typedef mozilla::dom::RTCStats RTCStats;

--- a/dom/webidl/RTCStatsReport.webidl
+++ b/dom/webidl/RTCStatsReport.webidl
@@ -180,16 +180,17 @@ dictionary RTCStatsReportInternal {
   sequence<RTCIceCandidatePairStats>      iceCandidatePairStats;
   sequence<RTCIceCandidateStats>          iceCandidateStats;
   sequence<RTCCodecStats>                 codecStats;
   DOMString                               localSdp;
   DOMString                               remoteSdp;
   DOMHighResTimeStamp                     timestamp;
   unsigned long                           iceRestarts;
   unsigned long                           iceRollbacks;
+  boolean                                 offerer; // Is the PC the offerer
   boolean                                 closed; // Is the PC now closed
 };
 
 [Pref="media.peerconnection.enabled",
 // TODO: Use MapClass here once it's available (Bug 928114)
 // MapClass(DOMString, object)
  JSImplementation="@mozilla.org/dom/rtcstatsreport;1"]
 interface RTCStatsReport {

--- a/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
+++ b/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
@@ -3668,16 +3668,17 @@ PeerConnectionImpl::BuildStatsQuery_m(
       std::string localDescription = mJsepSession->GetLocalDescription(
           kJsepDescriptionPendingOrCurrent);
       std::string remoteDescription = mJsepSession->GetRemoteDescription(
           kJsepDescriptionPendingOrCurrent);
       query->report->mLocalSdp.Construct(
           NS_ConvertASCIItoUTF16(localDescription.c_str()));
       query->report->mRemoteSdp.Construct(
           NS_ConvertASCIItoUTF16(remoteDescription.c_str()));
+      query->report->mOfferer.Construct(mJsepSession->IsOfferer());
     }
   }
 
   // Gather up pipelines from mMedia so they may be inspected on STS
 
   std::string trackId;
   if (aSelector) {
     trackId = PeerConnectionImpl::GetTrackId(*aSelector);

--- a/toolkit/content/aboutwebrtc/aboutWebrtc.js
+++ b/toolkit/content/aboutwebrtc/aboutWebrtc.js
@@ -474,29 +474,36 @@ function SDPStats(report) {
   this._report = report;
 }
 
 SDPStats.prototype = {
   render() {
     let div = document.createElement("div");
     let elem = document.createElement("h4");
 
+    let localSdpHeading = getString("local_sdp_heading");
+    let remoteSdpHeading = getString("remote_sdp_heading");
+    let offerLabel = `(${getString("offer")})`;
+    let answerLabel = `(${getString("answer")})`;
+
     elem.textContent = getString("sdp_heading");
     div.appendChild(elem);
 
     elem = document.createElement("h5");
-    elem.textContent = getString("local_sdp_heading");
+    elem.textContent =
+      `${localSdpHeading} ${this._report.offerer ? offerLabel : answerLabel}`;
     div.appendChild(elem);
 
     elem = document.createElement("pre");
     elem.textContent = this._report.localSdp;
     div.appendChild(elem);
 
     elem = document.createElement("h5");
-    elem.textContent = getString("remote_sdp_heading");
+    elem.textContent =
+      `${remoteSdpHeading} ${this._report.offerer ? answerLabel : offerLabel}`;
     div.appendChild(elem);
 
     elem = document.createElement("pre");
     elem.textContent = this._report.remoteSdp;
     div.appendChild(elem);
 
     return div;
   }

--- a/toolkit/locales/en-US/chrome/global/aboutWebrtc.properties
+++ b/toolkit/locales/en-US/chrome/global/aboutWebrtc.properties
@@ -44,16 +44,23 @@ peer_connection_id_label = PeerConnectio
 
 # LOCALIZATION NOTE (sdp_heading, local_sdp_heading, remote_sdp_heading):
 # "SDP" is an abbreviation for Session Description Protocol, an IETF standard.
 # See http://wikipedia.org/wiki/Session_Description_Protocol
 sdp_heading = SDP
 local_sdp_heading = Local SDP
 remote_sdp_heading = Remote SDP
 
+# LOCALIZATION NOTE (offer, answer):
+# offer and answer describe whether the local sdp is an offer or answer or
+# the remote sdp is an offer or answer.  These are appended to the local and
+# remote sdp headings.
+offer = Offer
+answer = Answer
+
 # LOCALIZATION NOTE (rtp_stats_heading): "RTP" is an abbreviation for the
 # Real-time Transport Protocol, an IETF specification, and should not
 # normally be translated. "Stats" is an abbreviation for Statistics.
 rtp_stats_heading = RTP Stats
 
 # LOCALIZATION NOTE (ice_state, ice_stats_heading): "ICE" is an abbreviation
 # for Interactive Connectivity Establishment, which is an IETF protocol,
 # and should not normally be translated. "Stats" is an abbreviation for