     console.log('config',config)
     if (config.sendOffer)
       console.log("Creating RTC offer to " + peer_id)
+      offerConstraints = {
+        "optional": [
+          { "OfferToReceiveAudio": true },
+          { "OfferToReceiveVideo": true },
+        ]
+      }
+      constraints = @mergeConstraints(offerConstraints, sdpConstraints)
+
       peer_connection.createOffer((local_description) =>
         console.log("Local offer description is: " + local_description)
         peer_connection.setLocalDescription(local_description

        )
      , (error) ->
        console.log("Error sending offer: "+error)
      )
    peer_connection


  # Peers exchange session descriptions which contains information

          , (error) ->
            console.log("Error creating answer: ", error)
            console.log(peer)
          ,sdpConstraints)
      ,(error) ->
        console.log("setRemoteDescription error: ", error)
      )
