support enable dtmf tone (#976)

* support enable dtmf tone

* wip

* wip

lib/utils/db-utils.js

@@ -215,11 +215,23 @@ module.exports = (logger, srf) => {
     }
   };
 
+  const lookupVoipCarrierBySid = async(sid) => {
+    const pp = pool.promise();
+    try {
+      const [r] = await pp.query('SELECT * FROM voip_carriers WHERE voip_carrier_sid = ?', [sid]);
+      return r;
+
+    } catch (err) {
+      logger.error({err}, `lookupVoipCarrierBySid: Error ${sid}`);
+    }
+  };
+
   return {
     lookupAccountDetails,
     updateSpeechCredentialLastUsed,
     lookupCarrier,
     lookupCarrierByPhoneNumber,
-    lookupGoogleCustomVoice
+    lookupGoogleCustomVoice,
+    lookupVoipCarrierBySid
   };
 };