Live video streaming using raspberry pi-3 and nginx-rtmp server over the internet (without port forwarding)?

Question

I am doing live video streaming over the internet with raspberry pi-3 from any where i want to access the live stream (without port forwarding).

So finally I have setup the nginx-rtmp server AWS on Ubuntu, and successfully completed single client streaming pi camera feed with raspberry pi-3 on the Internet using this server but the delay is about 6 to 9 seconds.

Our Approach

Set up nignx rtmp webserver on AWS EC ubuntu 16.04. sucessfully complete single client streaming Pi Camera Feed with raspberry pi 3 on internet using this server.

Our Problem
We are not able to stream multiple Pi camera with different raspberry pi 3 on nginx rtmp server with delay. We facing a larger delay of 8~10 second.

We want

We want to setup nginx rtmp server with multiple client (Raspberry Pi /Android APP user) which can handle all client load balance.

we have setup configuration file on linux based nginx rtmp server as follows:-

#user  nobody;
worker_processes  1;

error_log  logs/rtmp_error.log debug;
pid        logs/nginx.pid;

events {
    worker_connections  1024;
}

rtmp {
         server {
                listen 1935;
                chunk_size 4096;
                buflen 1ms;
                application cam_id {
                        live on;
                         allow publish 127.0.0.1;
                        allow publish all;
                        allow play all;
                        record all;
                        record_path /home/video_recordings;
                        record_unique on;
                        hls on;
                        hls_nested on;
                        hls_path /home/hls;
                        hls_fragment 10s;
                        dash on;
                        dash_path /home/dash;
                        dash_nested on;
        }

    }
}

We can play video streaming with

rtmp://server-ip/cam_id/live