diff --git a/.gitignore b/.gitignore
index 6adaeb6..fa7c007 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,6 @@ npm-debug.log
 node_modules
 node_modules/*
 /node_modules
+
+.vscode/
+src/amqp_BAK
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..3bca8b8
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,10 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+### Changed
+- Reduce usage of `var`
+- Use timeout instead of interval for resend messages to clients
diff --git a/package.json b/package.json
index 223a89e..fbcc4b1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "activestack-gateway",
-  "version": "0.2.5",
+  "version": "0.2.7",
   "release_date": "2016-05-03",
   "description": "Socket server for ActiveStack",
   "main": "src/main.js",
diff --git a/resources/env.default.properties b/resources/env.default.properties
index 920c60c..2d5eb51 100644
--- a/resources/env.default.properties
+++ b/resources/env.default.properties
@@ -33,3 +33,7 @@ gateway.rabbitmq.port=5672
 gateway.rabbitmq.login=guest
 gateway.rabbitmq.password=guest
 gateway.rabbitmq.durable=false
+
+frontend.clientMessageResendTimeout=7500
+frontend.clientMessageResendBackoff=1.5
+frontend.clientMessageResendAttempts=7
\ No newline at end of file
diff --git a/src/console.js b/src/console.js
index cb1fa9b..73faf9b 100644
--- a/src/console.js
+++ b/src/console.js
@@ -1,19 +1,19 @@
 'use strict';
 
-var redis = require("redis");
+const redis = require("redis");
 
 function GatewayConsoleApplication(){}
 module.exports = GatewayConsoleApplication;
 
 GatewayConsoleApplication.prototype.run = function(configFile) {
     configFile = configFile || __dirname + '/../resources/env.default.properties';
-    var properties = require('node-properties-parser').readSync(configFile);
+    const properties = require('node-properties-parser').readSync(configFile);
 
-    var gatewayControlQueue = properties['gateway.redis.gatewaycontrolqueue'];
+    let gatewayControlQueue = properties['gateway.redis.gatewaycontrolqueue'];
     if (!gatewayControlQueue)
         gatewayControlQueue = 'gateway';
 
-    var client = redis.createClient(properties['gateway.redis.port'], properties['gateway.redis.host']);
+    const client = redis.createClient(properties['gateway.redis.port'], properties['gateway.redis.host']);
     if (properties['gateway.redis.password']) {
         client.auth(properties['gateway.redis.password'], function (error, result) {
             if (error)
@@ -29,10 +29,8 @@ GatewayConsoleApplication.prototype.run = function(configFile) {
 
     process.stdin.resume();
     process.stdin.setEncoding('utf8');
-    var util = require('util');
 
     process.stdin.on('data', function (text) {
-        //console.log('received data:', util.inspect(text));
         if (text === 'quit\n') {
             done();
         }
diff --git a/src/server.js b/src/server.js
index 2e1522c..41c5447 100644
--- a/src/server.js
+++ b/src/server.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var cluster  = require('cluster'),
+const cluster  = require('cluster'),
     os       = require('os'),
     redis    = require('redis'),
     fs       = require('fs'),
@@ -25,7 +25,7 @@ GatewayServer.prototype.inject = function(prefixedLogger, properties, gatewayWor
 
 GatewayServer.prototype.start = function(){
 
-    var cpuCount = os.cpus().length;
+    const cpuCount = os.cpus().length;
     this.workerCount = this.properties['cluster.workerCount'] || cpuCount / 2 + 1;
 
     if(cluster.isMaster){
@@ -52,7 +52,7 @@ GatewayServer.prototype.isMaster = function(){
 GatewayServer.prototype.startMaster = function(){
     this.setupIPC();
 
-    for (var i = 0; i < this.workerCount; ++i) {
+    for (let i = 0; i < this.workerCount; ++i) {
         this.createWorkerProcess();
     }
 };
@@ -62,11 +62,11 @@ GatewayServer.prototype.startMaster = function(){
  */
 GatewayServer.prototype.setupIPC = function(){
     try {
-        var gatewayControlQueue = this.properties['gateway.redis.gatewaycontrolqueue'];
+        let gatewayControlQueue = this.properties['gateway.redis.gatewaycontrolqueue'];
         if (!gatewayControlQueue)
             gatewayControlQueue = 'gateway';
 
-        var client = redis.createClient(this.properties['gateway.redis.port'], this.properties['gateway.redis.host']);
+        const client = redis.createClient(this.properties['gateway.redis.port'], this.properties['gateway.redis.host']);
         if (this.properties['gateway.redis.password']) {
             client.auth(this.properties['gateway.redis.password'], function(error, result) {
                 if (error)
@@ -93,8 +93,8 @@ GatewayServer.prototype.setupIPC = function(){
  */
 GatewayServer.prototype.onIPCMessage = function (channel, message) {
     try {
-        var messageName = message.toLowerCase().trim();
-        var params = message.toLowerCase().trim().split(' ');
+        const messageName = message.toLowerCase().trim();
+        const params = message.toLowerCase().trim().split(' ');
 
         // TODO: Add workerCount message
         switch (messageName) {
@@ -129,7 +129,7 @@ GatewayServer.prototype.onIPCMessage = function (channel, message) {
 GatewayServer.prototype.onIPCShutdown = function(params){
     this.logger.info('Processing SHUTDOWN message');
     this.shuttingDown = true;
-    var stopCode;
+    let stopCode;
     if (params.length > 1) {
         stopCode = params[1];
     }
@@ -138,11 +138,11 @@ GatewayServer.prototype.onIPCShutdown = function(params){
         this.logger.info('\n************************ INVALID SHUTDOWN CODE RECEIVED!!! ************************\n');
         return;
     }
-    var stopType = 'immediate';
+    let stopType = 'immediate';
     if (params.length > 2) {
         stopType = params[2];
     }
-    var stopTimeout;
+    let stopTimeout;
     if (params.length > 3)
         stopTimeout = parseInt(params[3]);
     this.stopWorkerProcesses(stopType, stopTimeout);
@@ -154,11 +154,11 @@ GatewayServer.prototype.onIPCShutdown = function(params){
  */
 GatewayServer.prototype.onIPCRestart = function(params){
     this.logger.info('Processing RESTART message');
-    var restartType = 'immediate';
+    let restartType = 'immediate';
     if (params.length > 1) {
         restartType = params[1];
     }
-    var restartInterval;
+    let restartInterval;
     if (params.length > 2)
         restartInterval = parseInt(params[2]);
     this.restartWorkerProcesses(restartType, restartInterval);
@@ -179,7 +179,7 @@ GatewayServer.prototype.onIPCClientCount = function(){
 GatewayServer.prototype.onIPCClientMessageResendInterval = function(params){
     this.logger.info('Processing CLIENTMESSAGERESENDINTERVAL message');
 
-    var clientMessageResendInterval = this.properties['frontend.clientMessageResendInterval'];
+    let clientMessageResendInterval = this.properties['frontend.clientMessageResendInterval'];
     if (params.length > 1) {
         clientMessageResendInterval = params[1];
     }
@@ -192,7 +192,7 @@ GatewayServer.prototype.onIPCClientMessageResendInterval = function(params){
  */
 GatewayServer.prototype.onIPCLogLevel = function(params){
     this.logger.info('Processing LOGLEVEL message');
-    var logLevel = this.properties['frontend.logLevel'];
+    let logLevel = this.properties['frontend.logLevel'];
     if (params.length > 1) {
         logLevel = params[1];
     }
@@ -204,7 +204,7 @@ GatewayServer.prototype.startWorker = function(){
 };
 
 GatewayServer.prototype.restartWorkerProcesses = function(restartType, restartInterval) {
-    var oldWorkers = this.workers;
+    const oldWorkers = this.workers;
     this.workers = [];
     this.logger.info('Restarting processes - ' + restartType.toUpperCase());
 
@@ -212,13 +212,13 @@ GatewayServer.prototype.restartWorkerProcesses = function(restartType, restartIn
         if (!restartInterval)
             restartInterval = 500;
         this.logger.info('Restarting processes at ' + restartInterval + 'ms intervals');
-        for(var j=0; j<oldWorkers.length; j++) {
+        for(let j=0; j<oldWorkers.length; j++) {
             // Force it to stop. When the onEnd function runs it will restart it
             this.hardStopWorkerProcess(oldWorkers[j],j * restartInterval);
         }
     }
     else {
-        for(var j=0; j<oldWorkers.length; j++) {
+        for(let j=0; j<oldWorkers.length; j++) {
             this.logger.info('sending timeout ' + restartInterval);
             oldWorkers[j].send({cmd: 'restart', type: 'on_client_queue_empty', data: restartInterval});
         }
@@ -226,7 +226,7 @@ GatewayServer.prototype.restartWorkerProcesses = function(restartType, restartIn
 }
 
 GatewayServer.prototype.hardStopWorkerProcess = function(worker, delay){
-    var hardStop = function(){
+    const hardStop = function(){
         try {
             worker.disconnect();
             worker.destroy();
@@ -242,7 +242,7 @@ GatewayServer.prototype.hardStopWorkerProcess = function(worker, delay){
 };
 
 GatewayServer.prototype.stopAndRemoveWorkerProcess = function(worker, delay){
-    for(var i = 0; i < this.workers.length; i++) {
+    for(let i = 0; i < this.workers.length; i++) {
         if (this.workers[i] === worker) {
             this.workers.splice(i, 1);
             break;
@@ -252,7 +252,7 @@ GatewayServer.prototype.stopAndRemoveWorkerProcess = function(worker, delay){
 };
 
 GatewayServer.prototype.sendMessageToWorkers = function(message){
-    for(var j = 0; j < this.workers.length; j++) {
+    for(let j = 0; j < this.workers.length; j++) {
         try {
             if (this.workers[j]) {
                 this.workers[j].send(message);
@@ -267,7 +267,7 @@ GatewayServer.prototype.stopWorkerProcesses = function(stopType, stopTimeout) {
     this.logger.info('Stopping processes - ' + stopType.toUpperCase());
 
     if (stopType.toLowerCase() === 'immediate') {
-        for(var j = 0; j < this.workers.length; j++) {
+        for(let j = 0; j < this.workers.length; j++) {
             this.hardStopWorkerProcess(this.workers[j]);
         }
         process.exit();
@@ -297,8 +297,8 @@ GatewayServer.prototype.resetWorkerRestartDelay = function() {
 };
 
 GatewayServer.prototype.getNextWorkerRestartDelay = function() {
-    var failureCount = Math.min(this.consecutiveFailures++, this.properties['cluster.maxRestartBackoff']);
-    var factor = Math.random() * (Math.pow(2, failureCount) - 1);
+    const failureCount = Math.min(this.consecutiveFailures++, this.properties['cluster.maxRestartBackoff']);
+    const factor = Math.random() * (Math.pow(2, failureCount) - 1);
     return factor * this.properties['cluster.workerRestartDelay'];
 };
 
@@ -306,7 +306,7 @@ GatewayServer.prototype.onWorkerProcessOnline = function(worker) {
     this.logger.info('Worker online: ' + worker.process.pid);
     worker.lastHeartbeat = Date.now();
     worker.watchdog = setInterval(function() {
-        var time = Date.now();
+        const time = Date.now();
         if (worker.lastHeartbeat + this.properties['cluster.workerTimeout'] < time) {
             this.logger.info('Worker heartbeat stopped, destroying worker: ' + worker.process.pid);
 
@@ -322,9 +322,9 @@ GatewayServer.prototype.onWorkerProcessMessageHeartbeat = function(worker, messa
     }
 
     worker.lastHeartbeat = Date.now();
-    for (var type in message.memory) {
-        var limit = this.properties['cluster.memoryLimit.' + type];
-        var warning = this.properties['cluster.memoryWarning.' + type];
+    for (let type in message.memory) {
+        const limit = this.properties['cluster.memoryLimit.' + type];
+        const warning = this.properties['cluster.memoryWarning.' + type];
         if (limit && (message.memory[type] > limit * MEGABYTE)) {
             this.logger.info('Worker exceeded hard ' + type + ' memory limit (' +
                 message.memory[type] + '/' + limit * MEGABYTE + ')!');
@@ -393,7 +393,7 @@ GatewayServer.prototype.onWorkerProcessExit = function(worker, code, signal) {
         (signal || 'none') + ').  Starting replacement...');
     clearInterval(worker.watchdog);
 
-    for(var i = 0; i < this.workers.length; i++) {
+    for(let i = 0; i < this.workers.length; i++) {
         if (this.workers[i] === worker) {
             this.workers.splice(i, 1);
             break;
@@ -420,7 +420,7 @@ GatewayServer.prototype.createWorkerProcess = function(forceCreate) {
         }
     }
 
-    var worker = cluster.fork();
+    const worker = cluster.fork();
     worker.lastHeartbeat = null;
     worker.watchdog = null;
     worker.gotFirstHeartbeat = false;
diff --git a/src/server_application.js b/src/server_application.js
index 8bf5400..3dc9d7f 100644
--- a/src/server_application.js
+++ b/src/server_application.js
@@ -1,4 +1,4 @@
-var GatewayServer = require('./server'),
+const GatewayServer = require('./server'),
     AppContext = require('injecterooski').AppContext,
     PrefixedLogger = require('./logging/prefixed_logger'),
     HttpServerFactory = require('./factory/http_server_factory'),
@@ -14,9 +14,9 @@ var GatewayServer = require('./server'),
 function GatewayServerApplication(){}
 
 GatewayServerApplication.prototype.run = function(configFile){
-    var appContext = new AppContext();
+    const appContext = new AppContext();
 
-    var server = new GatewayServer();
+    const server = new GatewayServer();
 
     appContext.register([
         server,
diff --git a/src/service/client.js b/src/service/client.js
index a17fcdc..3117658 100644
--- a/src/service/client.js
+++ b/src/service/client.js
@@ -1,8 +1,8 @@
 'use strict';
 
-var Session = require('./session');
-var sys = require('util');
-var EventEmitter = require('events').EventEmitter;
+const Session = require('./session');
+const sys = require('util');
+const EventEmitter = require('events').EventEmitter;
 
 module.exports = GatewayClient;
 
@@ -31,8 +31,9 @@ function GatewayClient(socket, exchange, rabbitmq, logger, properties, sessionFa
 
     this.session = sessionFactory.create(); // Client's session, which also defines client's session ID (reconnectId)
 
+    this.awaitingResponseAcksCount = {}; // Holds counts for client message ACK's.
     this.awaitingResponseAcks = {}; // Holds callback functions for client message ACK's.
-    this.awaitingResponseAcksInterval = {}; // Message ACK Intervals for client message re-sends.
+    this.awaitingResponseAcksTimeout = {}; // Message ACK Timeouts for client message re-sends.
     this.clientQueue = null;    // Client RabbitMQ Queue
     this.disposed = false;
 
@@ -45,25 +46,26 @@ function GatewayClient(socket, exchange, rabbitmq, logger, properties, sessionFa
 GatewayClient.prototype.dispose = function() {
     if(this.disposed) return;
     this.disposed = true;
-    // Clear Awaiting Response Acks Intervals
-    if (this.awaitingResponseAcksInterval) {
-        for(var key in this.awaitingResponseAcksInterval) {
-            if (this.awaitingResponseAcksInterval.hasOwnProperty(key)) {
-                var theInterval = this.awaitingResponseAcksInterval[key];
-                this.logger.verbose('Clearing interval: ', theInterval);
+    // Clear Awaiting Response Acks Timeouts
+    if (this.awaitingResponseAcksTimeout) {
+        for(const key in this.awaitingResponseAcksTimeout) {
+            if (this.awaitingResponseAcksTimeout.hasOwnProperty(key)) {
+                const theTimeout = this.awaitingResponseAcksTimeout[key];
+                this.logger.verbose('Clearing timeout: ', theTimeout);
                 try {
-                    clearInterval(theInterval);
+                    clearTimeout(theTimeout);
                 } catch(error) { /* Do nothing on failure here */ }
             }
         }
-        this.awaitingResponseAcksInterval = {};
+        this.awaitingResponseAcksTimeout = {};
     }
 
     // Clear Awaiting Response Acks
+    this.awaitingResponseAcksCount = {};
     this.awaitingResponseAcks = {};
 
     // This sockect is completely closed, need to delete queue.
-    var disconnectMessage = this.session.populateMessage({
+    const disconnectMessage = this.session.populateMessage({
         cn: 'com.percero.agents.sync.vo.DisconnectRequest'
     });
     if (disconnectMessage.existingClientId) {
@@ -106,7 +108,7 @@ GatewayClient.prototype.init = function() {
     /**
      * SpecialMessageHandles - When the client receives a "special" message from the client, this defines how to process/handle
      *    that message.
-     *    - ack            Look for the corresponding ACK and acknowledge the message. Clear and remove any interval associated with the message.
+     *    - ack            Look for the corresponding ACK and acknowledge the message. Clear and remove any timeout associated with the message.
      *    - connect        Register new Auth agent and response queue (RabbitMQ Queue) for the client
      *    - hibernate        NOOP
      *    - reconnect    Attempt to initialize self using previous client settings, but with new client ID.
@@ -124,14 +126,14 @@ GatewayClient.prototype.init = function() {
 };
 
 GatewayClient.prototype.onHibernate = function(){
-    var hibernateMessage = this.session.populateMessage({
+    const hibernateMessage = this.session.populateMessage({
         cn: 'com.percero.agents.sync.vo.HibernateRequest'
     });
     this.sendToAgent('hibernate', hibernateMessage);
 }
 
 GatewayClient.prototype.onLogout = function(){
-    var disconnectAuthMessage = this.session.populateMessage({
+    const disconnectAuthMessage = this.session.populateMessage({
         cn: 'com.percero.agents.auth.vo.DisconnectRequest'
     });
     this.sendToAgent('disconnectAuth', disconnectAuthMessage);
@@ -139,7 +141,7 @@ GatewayClient.prototype.onLogout = function(){
 };
 
 GatewayClient.prototype.onAck = function(message) {
-    var ack = this.awaitingResponseAcks[message.correspondingMessageId];
+    const ack = this.awaitingResponseAcks[message.correspondingMessageId];
     if (!ack) {
         // We typically get here when:
         //  We re-sent the message because the client did not ACK in time, but in the meantime the client DID ACK and thus the re-send turned out to be superfluous.
@@ -150,15 +152,16 @@ GatewayClient.prototype.onAck = function(message) {
         delete this.awaitingResponseAcks[message.correspondingMessageId];
     }
 
-    var theInterval = this.awaitingResponseAcksInterval[message.correspondingMessageId];
-    if (theInterval) {
+    delete this.awaitingResponseAcksCount[message.correspondingMessageId];
+    const theTimeout = this.awaitingResponseAcksTimeout[message.correspondingMessageId];
+    if (theTimeout) {
         try {
-            clearInterval(theInterval);
+            clearTimeout(theTimeout);
         } catch(error) {
-            // If clearing the interval fails for whatever reason, we really don't care and want to move on.
+            // If clearing the timeout fails for whatever reason, we really don't care and want to move on.
         }
     }
-    delete this.awaitingResponseAcksInterval[message.correspondingMessageId];
+    delete this.awaitingResponseAcksTimeout[message.correspondingMessageId];
 };
 
 GatewayClient.prototype.onConnect = function() {
@@ -188,14 +191,14 @@ GatewayClient.prototype.onReconnect = function(message) {
 
     // The reconnectId is an encoded string that should contain all required details to re-establish the
     //  session, including the previous ClientID, which we save and then swap out for the new/current ClientID
-    var newClientId = this.session.clientId;
+    const newClientId = this.session.clientId;
     this.session.load(message.reconnectId); // Decrypts the reconnectId
     if (!this.session.existingClientIds) {
         this.session.existingClientIds = [];
     }
 
     // Setup the existing/previous client id(s)
-    var oldClientId = this.session.clientId;
+    const oldClientId = this.session.clientId;
     if (!oldClientId) {
         logger.error("No previous ClientID on reconnect");
     }
@@ -207,7 +210,7 @@ GatewayClient.prototype.onReconnect = function(message) {
     this.onConnect(message);
 
     if (this.session.isLoggedIn() && this.session.existingClientId && this.session.existingClientId !== this.session.clientId) {
-        var reconnectMessage = this.session.populateMessage({
+        const reconnectMessage = this.session.populateMessage({
             cn: 'com.percero.agents.sync.vo.ReconnectRequest',
             existingClientId: this.session.existingClientId,
             existingClientIds: this.session.existingClientIds
@@ -230,7 +233,7 @@ GatewayClient.prototype.onReconnect = function(message) {
 GatewayClient.prototype.routeSpecialMessage = function(type, message) {
     if (this.specialMessageHandlers[type]) {
         this.logger.verbose('Handling special message: ' + type + ' / ' + message);
-        var handler = this.specialMessageHandlers[type];
+        const handler = this.specialMessageHandlers[type];
         this[handler](message);
         this.sendSession();
     }
@@ -247,7 +250,7 @@ GatewayClient.prototype.sendSession = function() {
     this.session.isDirtyAsync(function(isDirty){
         if(isDirty){
             this.logger.verbose('Sending session to client.');
-            var signedSession = this.session.getSignedSession();
+            const signedSession = this.session.getSignedSession();
             this.sendToClient('gatewayConnectAck', signedSession);
         }
     }.bind(this));
@@ -258,8 +261,8 @@ GatewayClient.prototype.sendSession = function() {
  * @param response
  */
 GatewayClient.prototype.processResponse = function(response){
-    var regex = /^.*\.([^.]*)$/;
-    var relativeName = response.cn.replace(regex, '$1');
+    const regex = /^.*\.([^.]*)$/;
+    const relativeName = response.cn.replace(regex, '$1');
 
     switch(relativeName){
         case 'UserToken':
@@ -354,7 +357,7 @@ GatewayClient.prototype.afterLogin = function(){
     if(this.session.isLoggedIn()){
         // If the session has an existingClientId that is DIFFERENT from its clientId, then issue a ReconnectMessage instead.
         if (this.session.existingClientId && this.session.existingClientId !== this.session.clientId) {
-            var reconnectMessage = this.session.populateMessage({
+            const reconnectMessage = this.session.populateMessage({
                 cn: 'com.percero.agents.sync.vo.ReconnectRequest',
                 existingClientId: this.session.existingClientId,
                 existingClientIds: this.session.existingClientIds
@@ -364,7 +367,7 @@ GatewayClient.prototype.afterLogin = function(){
             this.sendToAgent('reconnect', reconnectMessage);
         }
         else {
-            var connectMessage = this.session.populateMessage({
+            const connectMessage = this.session.populateMessage({
                 cn: 'com.percero.agents.sync.vo.ConnectRequest'
             });
             this.logger.verbose('Connect Message for session client ' + this.session.clientId
@@ -424,7 +427,7 @@ GatewayClient.prototype.onClientQueueMessage = function(response, headers, info,
     this.sendSession(); // Send the updated session to the client.
 
     if (response.correspondingMessageId) {
-        this.setupResendInterval(response, receipt);
+        this.setupResendTimeout(response, receipt);
     } else {
         receipt.acknowledge();
     }
@@ -433,41 +436,56 @@ GatewayClient.prototype.onClientQueueMessage = function(response, headers, info,
 };
 
 /**
- * Setup an interval to resend the message, at some interval until the client acks
+ * Setup an timeout to resend the message, at some timeout until the client acks
  * @param theResponse
  * @param receipt
  */
-GatewayClient.prototype.setupResendInterval = function(theResponse, receipt) {
+GatewayClient.prototype.setupResendTimeout = function(theResponse, receipt) {
     // Setup callback function to be used when the 'onAck' function is called for this message
     this.awaitingResponseAcks[theResponse.correspondingMessageId] = function() {
         receipt.acknowledge();
     };
 
-    this.awaitingResponseAcksInterval[theResponse.correspondingMessageId] =
-        setInterval(this.resend.bind(this, theResponse),
-            (this.properties['frontend.clientMessageResendInterval'] || 7500));
+    this.awaitingResponseAcksCount[theResponse.correspondingMessageId] = 1;
+
+    // console.log('Setting Ack Timeout: ' + (this.properties['frontend.clientMessageResendInterval'] || this.properties['frontend.clientMessageResendTimeout'] || 7500));
+    this.awaitingResponseAcksTimeout[theResponse.correspondingMessageId] =
+        setTimeout(this.resend.bind(this, theResponse),
+            (this.properties['frontend.clientMessageResendInterval'] || this.properties['frontend.clientMessageResendTimeout'] || 7500));
 };
 
 /**
- * Callback function to the interval setup in setupResendInterval. Tries to resend the
+ * Callback function to the timeout setup in setupResendTimeout. Tries to resend the
  * message.
  *
  * @param theResponse
  */
 GatewayClient.prototype.resend = function(theResponse) {
-    var ack = this.awaitingResponseAcks[theResponse.correspondingMessageId];
+    const ack = this.awaitingResponseAcks[theResponse.correspondingMessageId];
     if (ack) {
-        this.logger.warn('Unacknowledged message being sent again: ', theResponse.correspondingMessageId);
-        this.sendToClient('push', theResponse);
-    }
-    else {
-        var theInterval = this.awaitingResponseAcksInterval[theResponse.correspondingMessageId];
-        if (theInterval) {
-            this.logger.verbose('Message acknowledged, clearing timer.');
-            clearInterval(theInterval);
+        this.awaitingResponseAcksCount[theResponse.correspondingMessageId]++;
+        const ackCount = this.awaitingResponseAcksCount[theResponse.correspondingMessageId];
+
+        if (ackCount <= this.properties['frontend.clientMessageResendAttempts'] || 7) {
+            this.logger.warn('Unacknowledged message being sent again: ', theResponse.correspondingMessageId);
+            this.sendToClient('push', theResponse);
+            console.log('Setting Ack Timeout: ' + ((this.properties['frontend.clientMessageResendInterval'] || this.properties['frontend.clientMessageResendTimeout'] || 7500) * Math.pow((this.properties['frontend.clientMessageResendBackoff'] || 1.5), ackCount)));
+            this.awaitingResponseAcksTimeout[theResponse.correspondingMessageId] = 
+                setTimeout(this.resend.bind(this, theResponse),
+                    ((this.properties['frontend.clientMessageResendInterval'] || this.properties['frontend.clientMessageResendTimeout'] || 7500) * Math.pow((this.properties['frontend.clientMessageResendBackoff'] || 1.5), ackCount)));
+            return;
         }
-        delete this.awaitingResponseAcksInterval[theResponse.correspondingMessageId];
     }
+
+    delete this.awaitingResponseAcksCount[theResponse.correspondingMessageId];
+    delete this.awaitingResponseAcks[theResponse.correspondingMessageId];
+
+    const theTimeout = this.awaitingResponseAcksTimeout[theResponse.correspondingMessageId];
+    if (theTimeout) {
+        this.logger.verbose('Message acknowledged, clearing timeout.');
+        clearTimeout(theTimeout);
+    }
+    delete this.awaitingResponseAcksTimeout[theResponse.correspondingMessageId];
 }
 
 /**
@@ -475,7 +493,7 @@ GatewayClient.prototype.resend = function(theResponse) {
  * @param queue
  */
 GatewayClient.prototype.onClientQueueCreation = function(queue) {
-    var options = { ack: true, prefetchCount: 10 };
+    const options = { ack: true, prefetchCount: 10 };
 
     // Setup subscription to the new queue.
     queue.subscribe(options, this.onClientQueueMessage.bind(this));
diff --git a/src/service/gateway.js b/src/service/gateway.js
index 8fa879b..6e0cf6f 100644
--- a/src/service/gateway.js
+++ b/src/service/gateway.js
@@ -1,8 +1,7 @@
 'use strict';
 
-var io = require('socket.io');
-var Client = require('./client');
-var RedisStore = require('socket.io/lib/stores/redis');
+const io = require('socket.io');
+const Client = require('./client');
 
 module.exports = Gateway;
 
@@ -73,8 +72,8 @@ Gateway.prototype.initRabbitMQ = function() {
 
 Gateway.prototype.onRabbitReady = function () {
     this.logger.debug("RabbitMQ connection ready");
-    var durable = this.properties['gateway.rabbitmq.durable'] == 'true';
-    var options = {autoDelete: false, durable: durable, confirm: true};
+    const durable = this.properties['gateway.rabbitmq.durable'] == 'true';
+    const options = {autoDelete: false, durable: durable, confirm: true};
     this.exchange = this.rabbitmq.exchange('', options);
 
     this.exchange.on('error', this.gatewayWorker.createErrorHandler('RabbitMQ Exchange'));
@@ -86,7 +85,7 @@ Gateway.prototype.onRabbitReady = function () {
 }
 
 Gateway.prototype.onSocketEnd = function (socket, isServerTerminated) {
-    var client = this.clients[socket.id];
+    const client = this.clients[socket.id];
     if (client) {
         client.isServerTerminated = isServerTerminated;
     }
@@ -110,6 +109,13 @@ Gateway.prototype.onSocketEnd = function (socket, isServerTerminated) {
             data: (!this.sockets || Object.keys(this.sockets).length <= 0) ? 0 : Object.keys(this.sockets).length
         });
     } catch (error) {}
+
+    setTimeout(function(socket, logger) {
+        try {
+            // Make sure the socket is disconnected/destroyed.
+            socket.end();
+        } catch(error) {}
+    },0, socket, this.logger);
 };
 
 Gateway.prototype.onSocketDisconnect = function (socket, reason, isServerTerminated) {
@@ -144,7 +150,7 @@ Gateway.prototype.onSocketConnection = function (socket) {
     socket.on('disconnect', this.onSocketDisconnect.bind(this, socket));
     socket.on('logout', this.onSocketLogout.bind(this, socket));
 
-    var newClient = new Client(socket, this.exchange, this.rabbitmq, this.logger, this.properties, this.sessionFactory);
+    const newClient = new Client(socket, this.exchange, this.rabbitmq, this.logger, this.properties, this.sessionFactory);
     this.clients[socket.id] = newClient;
 
     newClient.on('dispose', this.onClientDispose.bind(this, socket));
@@ -152,7 +158,7 @@ Gateway.prototype.onSocketConnection = function (socket) {
 
 
 Gateway.prototype.handleError = function(error, source) {
-    var catchAndWarn = this.gatewayWorker.catchAndWarn;
+    const catchAndWarn = this.gatewayWorker.catchAndWarn;
 
     catchAndWarn('RabbitMQ', function() { this.rabbitmq.end();}.bind(this));
 
@@ -185,7 +191,7 @@ Gateway.prototype.onShutdown = function(shutdownType) {
 
     // RedisClient resists proper error handling :-(
 Gateway.prototype.attachRedisErrorHandlers = function(type, redis) {
-    var handler = this.gatewayWorker.createErrorHandler('Redis Store ' + type);
+    const handler = this.gatewayWorker.createErrorHandler('Redis Store ' + type);
     redis.on('error', handler);
 
     // If the server shuts down we get an "end" instead of an error.
diff --git a/src/service/session.js b/src/service/session.js
index 0b3f670..34aecf4 100644
--- a/src/service/session.js
+++ b/src/service/session.js
@@ -1,9 +1,9 @@
 'use strict';
 
 // TODO: Implement rolling session secret.
-var MAX_SESSION_AGE = (new Date(0)).setUTCDate(7);  // 7 days
+const MAX_SESSION_AGE = (new Date(0)).setUTCDate(7);  // 7 days
 
-var crypto = require('crypto');
+const crypto = require('crypto');
 
 module.exports = Session;
 
@@ -56,7 +56,7 @@ Session.prototype.clone = function(copy) {
 };
 
 Session.prototype.signSession = function(encodedSession) {
-    var hmac = crypto.createHmac('sha512', this.properties['frontend.session_secret'] || 'twothreefour');
+    const hmac = crypto.createHmac('sha512', this.properties['frontend.session_secret'] || 'twothreefour');
     hmac.update(encodedSession);
 
     return hmac.digest('base64');
@@ -71,9 +71,9 @@ Session.prototype.signSession = function(encodedSession) {
  */
 Session.prototype.getSignedSession = function() {
     this._dirty = false;
-    var jsonCopy = JSON.stringify(this.clone({ savedAt: Date.now() }));
+    const jsonCopy = JSON.stringify(this.clone({ savedAt: Date.now() }));
 
-    var encodedSession = new Buffer(jsonCopy).toString('base64');
+    const encodedSession = new Buffer(jsonCopy).toString('base64');
     return (encodedSession + ';' + this.signSession(encodedSession));
 };
 
@@ -99,7 +99,7 @@ Session.prototype.isDirtyAsync = function(callback){
  */
 Session.prototype.load = function(signedSession) {
     if (signedSession && (typeof signedSession.split == 'function')) {
-        var parts = signedSession.split(';');
+        const parts = signedSession.split(';');
     } else {
         this.logger.warn('Dropping invalid session: ' + signedSession);
         return false;
@@ -110,15 +110,15 @@ Session.prototype.load = function(signedSession) {
         return false;
     }
 
-    var encodedSession = parts[0];
-    var signature = parts[1];
+    const encodedSession = parts[0];
+    const signature = parts[1];
 
     if (signature != this.signSession(encodedSession)) {
         this.logger.warn('Dropping (potentially) tampered session: ' + signedSession);
         return false;
     }
 
-    var copy = JSON.parse(new Buffer(encodedSession, 'base64').toString());
+    const copy = JSON.parse(new Buffer(encodedSession, 'base64').toString());
     if (copy.savedAt < Date.now() - MAX_SESSION_AGE) {
         this.logger.warn('Dropping expired session: ' + signedSession);
         return false;
@@ -133,7 +133,7 @@ Session.prototype.load = function(signedSession) {
     // Dirty ourselves so the client gets an update with a newer timestamp.
     this._dirty = true;
 
-    var leftovers = Object.keys(copy);
+    const leftovers = Object.keys(copy);
     if (leftovers.length > 0) {
         this.logger.warn('Dropping unexpected session keys ' +
         JSON.stringify(leftovers) + ': ' + signedSession);
diff --git a/src/worker.js b/src/worker.js
index c3f7ceb..1afef77 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -22,11 +22,11 @@ GatewayWorker.prototype.isExiting = function(){
 };
 
 GatewayWorker.prototype.checkMemoryUsage = function () {
-    var memoryUsage = process.memoryUsage();
-    var megabyte = 1024 * 1024;
-    for (var type in memoryUsage) {
-        var limit = this.properties['cluster.memoryLimit.' + type];
-        var warning = this.properties['cluster.memoryWarning.' + type];
+    const memoryUsage = process.memoryUsage();
+    const megabyte = 1024 * 1024;
+    for (let type in memoryUsage) {
+        const limit = this.properties['cluster.memoryLimit.' + type];
+        const warning = this.properties['cluster.memoryWarning.' + type];
         if (limit && (memoryUsage[type] > limit * megabyte)) {
             this.logger.error('Worker exceeded hard ' + type + ' memory limit (' +
             memoryUsage[type] + '/' + limit * megabyte + ')!');
@@ -53,9 +53,9 @@ GatewayWorker.prototype.sendMessage = function(message) {
 
 
 GatewayWorker.prototype.onMessageStopOrRestart = function(msg){
-    var cmd = msg.cmd;
-    var type = msg.type;
-    var data = parseInt(msg.data);
+    const cmd = msg.cmd;
+    const type = msg.type;
+    const data = parseInt(msg.data);
     this.logger.info('server received '+msg.cmd+' message: ' + type);
     if (type.toLowerCase() === 'on_client_queue_empty') {
 
@@ -86,14 +86,14 @@ GatewayWorker.prototype.onMessageStopOrRestart = function(msg){
 
 GatewayWorker.prototype.onMessageLogLevel = function(msg){
     throw new Error('NOT IMPLEMENTED');
-    //var logLevel = msg.data;
+    //const logLevel = msg.data;
     //this.logger.info('Setting LogLevel to ' + logLevel);
     //logger.remove(winston.transports.Console);
     //logger.add(winston.transports.Console, {level: logLevel});
 };
 
 GatewayWorker.prototype.onMessageCMSI = function(msg){
-    var clientMessageResendInterval = msg.data;
+    const clientMessageResendInterval = msg.data;
     this.logger.info('Setting clientMessageResendInterval to ' + clientMessageResendInterval);
     this.properties['frontend.clientMessageResendInterval'] = clientMessageResendInterval;
 };
@@ -104,7 +104,7 @@ GatewayWorker.prototype.onMessageClientCount = function(msg){
 };
 
 GatewayWorker.prototype.onProcessMessage = function (msg) {
-    var command = msg.cmd.toLowerCase();
+    const command = msg.cmd.toLowerCase();
     switch(command){
         case 'restart':
             this.onMessageStopOrRestart(msg);