diff --git a/src/config.js b/src/config.js
index 31ce984a..5ef4e417 100644
--- a/src/config.js
+++ b/src/config.js
@@ -107,11 +107,6 @@ export const LINK_PRIVACY_POLICY = 'https://tinode.co/privacy.html';
 // Link to Terms of Service.
 export const LINK_TERMS_OF_SERVICE = 'https://tinode.co/terms.html';
 
-// Video call states.
-export const CALL_STATE_NONE = 0;
-export const CALL_STATE_OUTGOING_INITATED = 1;
-export const CALL_STATE_INCOMING_RECEIVED = 2;
-export const CALL_STATE_IN_PROGRESS = 3;
 // Video calls/WebRTC configuration.
 export const CALL_WEBRTC_CONFIG = {
   iceServers: [
diff --git a/src/constants.js b/src/constants.js
new file mode 100644
index 00000000..bebdf415
--- /dev/null
+++ b/src/constants.js
@@ -0,0 +1,8 @@
+// Video call states.
+export const CALL_STATE_NONE = 0;
+export const CALL_STATE_OUTGOING_INITATED = 1;
+export const CALL_STATE_INCOMING_RECEIVED = 2;
+export const CALL_STATE_IN_PROGRESS = 3;
+
+// Mime type used for video call messages.
+export const CALL_MESSAGE_MIME_TYPE = 'application/x-tinode-webrtc';
diff --git a/src/lib/utils.js b/src/lib/utils.js
index 46944715..cc12e54c 100644
--- a/src/lib/utils.js
+++ b/src/lib/utils.js
@@ -2,6 +2,8 @@
 
 import { Tinode } from 'tinode-sdk';
 
+import { CALL_MESSAGE_MIME_TYPE } from '../constants.js'
+
 // Make shortcut icon appear with a green dot + show unread count in title.
 export function updateFavicon(count) {
   const oldIcon = document.getElementById('shortcut-icon');
@@ -208,7 +210,7 @@ export function cancelablePromise(promise) {
 
 // Returns true if specified mime type represents a Tinode video call.
 export function isVideoCall(mime) {
-  return mime == 'application/tinode-video-call';
+  return mime == CALL_MESSAGE_MIME_TYPE;
 }
 
 // Clips string to the specified length.
diff --git a/src/views/incoming-call-view.jsx b/src/views/incoming-call-view.jsx
index 277052e3..e7b07054 100644
--- a/src/views/incoming-call-view.jsx
+++ b/src/views/incoming-call-view.jsx
@@ -1,21 +1,20 @@
 // IncomingCallView: displays Accept & Reject buttons for incoming calls.
 import React from 'react';
-import { FormattedMessage, injectIntl } from 'react-intl';
-
-import Tinode from 'tinode-sdk';
+import { FormattedMessage } from 'react-intl';
 
 import AvatarUpload from '../widgets/avatar-upload.jsx';
 import BadgeList from '../widgets/badge-list.jsx';
 import MenuCancel from '../widgets/menu-cancel.jsx';
 
-import { CALL_STATE_INCOMING_RECEIVED, MAX_TITLE_LENGTH } from '../config.js';
+import { MAX_TITLE_LENGTH } from '../config.js';
+import { CALL_STATE_INCOMING_RECEIVED } from '../constants.js';
 
 import { makeImageUrl } from '../lib/blob-helpers.js';
 import { clipStr } from '../lib/utils.js'
 
-const RING_SOUND = new Audio("audio/phone_ring.mp3");
+const RING_SOUND = new Audio('audio/phone_ring.mp3');
 
-class IncomingCallView extends React.Component {
+export default class IncomingCallView extends React.Component {
   constructor(props) {
     super(props);
 
@@ -119,12 +118,8 @@ class IncomingCallView extends React.Component {
   }
 
   render() {
-    const {formatMessage} = this.props.intl;
-    let panelTitle = 'Unknown';
-    if (this.props.callState == CALL_STATE_INCOMING_RECEIVED) {
-      panelTitle = <FormattedMessage id="calls_incoming_title"
-          defaultMessage="Incoming Call" description="Incoming call title (Incoming call view)" />;
-    }
+    let panelTitle = <FormattedMessage id="calls_incoming_title"
+        defaultMessage="Incoming Call" description="Incoming call title (Incoming call view)" />;
 
     return (
       <div id="info-view">
@@ -170,5 +165,3 @@ class IncomingCallView extends React.Component {
     );
   }
 };
-
-export default injectIntl(IncomingCallView);
diff --git a/src/views/messages-view.jsx b/src/views/messages-view.jsx
index 22a12aa2..cf7dd4cc 100644
--- a/src/views/messages-view.jsx
+++ b/src/views/messages-view.jsx
@@ -21,10 +21,12 @@ import SendMessage from '../widgets/send-message.jsx';
 
 import { DEFAULT_P2P_ACCESS_MODE, IMAGE_PREVIEW_DIM, KEYPRESS_DELAY,
   MESSAGES_PAGE, MAX_EXTERN_ATTACHMENT_SIZE, MAX_IMAGE_DIM, MAX_INBAND_ATTACHMENT_SIZE,
-  READ_DELAY, QUOTED_REPLY_LENGTH, CALL_STATE_OUTGOING_INITATED, CALL_STATE_IN_PROGRESS } from '../config.js';
+  READ_DELAY, QUOTED_REPLY_LENGTH } from '../config.js';
+import { CALL_STATE_OUTGOING_INITATED, CALL_STATE_IN_PROGRESS } from '../constants.js';
 import { blobToBase64, fileToBase64, imageScaled, makeImageUrl } from '../lib/blob-helpers.js';
 import HashNavigation from '../lib/navigation.js';
 import { bytesToHumanSize, shortDateFormat } from '../lib/strformat.js';
+import { isVideoCall } from '../lib/utils.js';
 
 // Run timer with this frequency (ms) for checking notification queue.
 const NOTIFICATION_EXEC_INTERVAL = 300;
@@ -177,7 +179,6 @@ class MessagesView extends React.Component {
       if (prevState.topic && !Tinode.isNewGroupTopicName(prevState.topic)) {
         this.leave(prevState.topic);
         if (prevState.rtcPanel) {
-          console.log('hangup: ', prevState.topic);
           this.handleCallHangup(prevState.topic, prevProps.callSeq);
         }
       }
@@ -1146,13 +1147,21 @@ class MessagesView extends React.Component {
               );
               prevDate = thisDate;
             }
+            let duration;
+            if (msg.head && isVideoCall(msg.head.mime)) {
+              topic.messageVersions(msg, (cur, before, unused1, unused2) => {
+                if (cur.content == 'finished' && before.content == 'accepted') {
+                  duration = msg.ts - before.ts;
+                }
+              });
+            }
             messageNodes.push(
               <ChatMessage
                 tinode={this.props.tinode}
                 content={msg.content}
                 mimeType={msg.head ? msg.head.mime : null}
                 timestamp={msg.ts}
-                duration={msg.origTs ? msg.ts - msg.origTs : null}
+                duration={duration}
                 response={isReply}
                 seq={msg.seq}
                 isGroup={groupTopic}
diff --git a/src/views/tinode-web.jsx b/src/views/tinode-web.jsx
index 8c11cd46..f762989d 100644
--- a/src/views/tinode-web.jsx
+++ b/src/views/tinode-web.jsx
@@ -18,9 +18,10 @@ import MessagesView from './messages-view.jsx';
 import SidepanelView from './sidepanel-view.jsx';
 
 import { API_KEY, APP_NAME, DEFAULT_P2P_ACCESS_MODE, FORWARDED_PREVIEW_LENGTH, LOGGING_ENABLED,
-  MEDIA_BREAKPOINT, RECEIVED_DELAY,
-  CALL_STATE_NONE, CALL_STATE_OUTGOING_INITATED,
-  CALL_STATE_INCOMING_RECEIVED, CALL_STATE_IN_PROGRESS } from '../config.js';
+  MEDIA_BREAKPOINT, RECEIVED_DELAY } from '../config.js';
+import { CALL_STATE_NONE, CALL_STATE_OUTGOING_INITATED,
+         CALL_STATE_INCOMING_RECEIVED, CALL_STATE_IN_PROGRESS,
+         CALL_MESSAGE_MIME_TYPE }  from '../constants.js';
 import { PACKAGE_VERSION } from '../version.js';
 import { base64ReEncode, makeImageUrl } from '../lib/blob-helpers.js';
 import { detectServerAddress, isLocalHost, isSecureConnection } from '../lib/host-name.js';
@@ -1037,7 +1038,7 @@ class TinodeWeb extends React.Component {
 
     // TODO: check if return is required.
     return topic.publishDraft(msg, Promise.all(completion))
-      .then(_ => {
+      .then((ctrl) => {
         if (topic.isArchived()) {
           topic.archive(false);
         }
@@ -1698,11 +1699,10 @@ class TinodeWeb extends React.Component {
   handleCallInvite(callTopic, callSeq, callState) {
     switch (callState) {
       case CALL_STATE_OUTGOING_INITATED:
-        let head = {mime: 'application/tinode-video-call'};
+        let head = {mime: CALL_MESSAGE_MIME_TYPE };
         this.handleSendMessage('started', undefined, undefined, head)
           .then((ctrl) => {
-            if (ctrl.code < 200 || ctrl.code >= 300 ||
-                typeof ctrl.params == 'undefined' || typeof ctrl.params['seq'] == 'undefined') {
+            if (ctrl.code < 200 || ctrl.code >= 300 || !ctrl.params || !ctrl.params.seq) {
               this.handleCallClose();
               return;
             }
@@ -1715,7 +1715,7 @@ class TinodeWeb extends React.Component {
           return;
         }
         // We've accepted the call. Let the other side know.
-        topic.call('accept', callSeq).catch((err) => {
+        topic.videoCall('accept', callSeq).catch((err) => {
           this.handleCallClose();
           this.handleError(err.message, 'err');
         });
@@ -1729,7 +1729,7 @@ class TinodeWeb extends React.Component {
       return;
     }
 
-    topic.call('ringing', callSeq);
+    topic.videoCall('ringing', callSeq);
   }
 
   handleCallHangup(callTopic, callSeq) {
@@ -1738,7 +1738,7 @@ class TinodeWeb extends React.Component {
       return;
     }
 
-    topic.call('hang-up', callSeq);
+    topic.videoCall('hang-up', callSeq);
   }
 
   handleCallSendOffer(callTopic, callSeq, sdp) {
@@ -1747,7 +1747,7 @@ class TinodeWeb extends React.Component {
       return;
     }
 
-    topic.call('offer', callSeq, sdp);
+    topic.videoCall('offer', callSeq, sdp);
   }
 
   handleCallIceCandidate(callTopic, callSeq, candidate) {
@@ -1756,7 +1756,7 @@ class TinodeWeb extends React.Component {
       return;
     }
 
-    topic.call('ice-candidate', callSeq, candidate);
+    topic.videoCall('ice-candidate', callSeq, candidate);
   }
   handleCallSendAnswer(callTopic, callSeq, sdp) {
     const topic = this.tinode.getTopic(callTopic);
@@ -1764,7 +1764,7 @@ class TinodeWeb extends React.Component {
       return;
     }
 
-    topic.call('answer', callSeq, sdp);
+    topic.videoCall('answer', callSeq, sdp);
   }
 
   handleCallClose() {
@@ -1802,7 +1802,6 @@ class TinodeWeb extends React.Component {
     }
     switch (info.event) {
       case 'invite':
-        console.log('invite: ', info);
         if (info.from != this.state.myUserId) {
           // Incoming call.
           this.setState({
diff --git a/src/widgets/call-panel.jsx b/src/widgets/call-panel.jsx
index d6a79549..610309cc 100644
--- a/src/widgets/call-panel.jsx
+++ b/src/widgets/call-panel.jsx
@@ -4,8 +4,8 @@ import { FormattedMessage } from 'react-intl';
 
 import LetterTile from '../widgets/letter-tile.jsx';
 
-import { CALL_STATE_OUTGOING_INITATED, CALL_STATE_IN_PROGRESS, CALL_WEBRTC_CONFIG,
-         MAX_TITLE_LENGTH } from '../config.js';
+import { CALL_WEBRTC_CONFIG, MAX_TITLE_LENGTH } from '../config.js';
+import { CALL_STATE_OUTGOING_INITATED, CALL_STATE_IN_PROGRESS } from '../constants.js';
 
 import { clipStr } from '../lib/utils.js'
 
@@ -64,19 +64,16 @@ export default class CallPanel extends React.PureComponent {
     const pc = this.createPeerConnection();
     const stream = this.state.localStream;
     stream.getTracks().forEach(track => {
-      console.log('local stream adding track ', track.id, track.kind, track.readyState);
       pc.addTrack(track, stream);
     });
   }
 
   onInfo(info) {
-    console.log('info --> ', info);
     if (info.what != 'call') {
       return;
     }
     switch (info.event) {
       case 'accept':
-        // Call accepted.
         this.handleVideoCallAccepted(info);
         break;
       case 'offer':
@@ -106,7 +103,6 @@ export default class CallPanel extends React.PureComponent {
 
   componentWillUnmount() {
     this.props.topic.onInfo = this.previousOnInfo;
-    console.log('will unmount. stop');
     this.stop();
   }
 
@@ -143,16 +139,12 @@ export default class CallPanel extends React.PureComponent {
     pc.ontrack = this.handleTrackEvent;
 
     this.setState({pc: pc});
-    console.log('Created RTCPeerConnnection');
     return pc;
   }
 
   handleVideoAnswerMsg(info) {
-    console.log("*** Call recipient has accepted our call");
-
     // Configure the remote description, which is the SDP payload
-    // in our "video-answer" message.
-
+    // in 'info' message.
     var desc = new RTCSessionDescription(info.payload);
     this.state.pc.setRemoteDescription(desc).catch(this.reportError);
   }
@@ -186,18 +178,16 @@ export default class CallPanel extends React.PureComponent {
 
   handleICEConnectionStateChangeEvent(event) {
     switch (this.state.pc.iceConnectionState) {
-      case "closed":
-      case "failed":
+      case 'closed':
+      case 'failed':
         this.handleCloseClick();
         break;
     }
   }
 
   handleSignalingStateChangeEvent(event) {
-    switch (this.state.pc.signalingState) {
-      case "closed":
-        this.handleCloseClick();
-        break;
+    if (this.state.pc.signalingState == 'closed') {
+      this.handleCloseClick();
     }
   }
 
@@ -212,18 +202,17 @@ export default class CallPanel extends React.PureComponent {
   }
 
   handleGetUserMediaError(e) {
-    console.log('-->', e);
     switch(e.name) {
-      case "NotFoundError":
+      case 'NotFoundError':
         console.log("Unable to open your call because no camera and/or microphone" +
               "were found.");
         break;
-      case "SecurityError":
-      case "PermissionDeniedError":
+      case 'SecurityError':
+      case 'PermissionDeniedError':
         // Do nothing; this is the same as the user canceling the call.
         break;
       default:
-        console.log("Error opening your camera and/or microphone: " + e.message);
+        console.log('Error opening your camera and/or microphone: ' + e.message);
         break;
     }
 
@@ -240,7 +229,6 @@ export default class CallPanel extends React.PureComponent {
     var desc = new RTCSessionDescription(info.payload);
 
     pc.setRemoteDescription(desc).then(() => {
-      console.log('!!! handleVideoOffer/setRemoteDescription -> getUserMesia');
       return navigator.mediaDevices.getUserMedia(this.localStreamConstraints);
     })
     .then(stream => {
@@ -249,7 +237,6 @@ export default class CallPanel extends React.PureComponent {
       this.setState({localStream: stream});
 
       localStream.getTracks().forEach(track => {
-        console.log('local stream A adding track ', track.id, track.kind, track.readyState);
         pc.addTrack(track, localStream);
       });
     })
@@ -279,7 +266,6 @@ export default class CallPanel extends React.PureComponent {
       tracks.forEach((track) => {
         track.stop();
         track.enabled = false;
-        console.log('stopped track ', track.id, track.kind, track.readyState);
       });
     }
     el.srcObject = null;
@@ -316,7 +302,6 @@ export default class CallPanel extends React.PureComponent {
       if (track.kind != kind) {
         return;
       }
-      console.log('local stream: toggling track ', track.id, track.kind, track.readyState);
       track.enabled = !track.enabled;
     });
     // Make sure we redraw the UI properly.
diff --git a/src/widgets/chat-message.jsx b/src/widgets/chat-message.jsx
index 276a07ea..0b66eff3 100644
--- a/src/widgets/chat-message.jsx
+++ b/src/widgets/chat-message.jsx
@@ -149,7 +149,7 @@ class BaseChatMessage extends React.PureComponent {
       </i></>
     } else if (isVideoCall(this.props.mimeType)) {
       // Video calls.
-      const direction = this.props.response ? "call_received" : "call_made";
+      const direction = this.props.response ? 'call_received' : 'call_made';
       const text = this.props.response ?
         <FormattedMessage id="calls_incoming"
           defaultMessage="Incoming Call" description="Incoming call label" /> :
@@ -157,7 +157,7 @@ class BaseChatMessage extends React.PureComponent {
           defaultMessage="Outgoing Call" description="Outgoing call label" />;
       const isCallDropped = this.props.content == "disconnected";
       content = <><i className="material-icons" style={{color: isCallDropped ? "red" : "green"}}>{direction}</i>{text}
-        { !isCallDropped ?
+        { !isCallDropped && this.props.duration ?
           [' (', <FormattedDuration seconds={this.props.duration / 1000} format="{hours} {minutes} {seconds}" />, ')'] :
           null}
       </>