# eMQTT Desgin Guide

## KeepAlive

## Retained

## QOS1 

## QOS2

## Durable Subscriptions

Durable Sub:

Client->Queue->Router->Queue->Client

Normal Sub:

Client->Router->Client

Router to register queues

## Topic Tree

## Offline Message

## ACL

## Authentication with clientId

## SSL/TLS Socket

## $SYS/topics and Broker statistics...

## Cluster 

## Bridge