I am a little confused about how can i start to explain dual wan load balancing to answer some of your requests, I think already a lot to explain about load balancing. I hope you do not just wait from me or be based on one reference only, before you really can implement load balancing in accordance with the problems you found and apply them optimally. Again, my experience is just reference for you. I also apologize for those of you who waited patiently for the results of my experiment.
Because of inability of me to pay the cost of connection broadband ISP services, my hopes seemed to disappear to continue of the small businesses of internet shop which I have lived for 5 years. So many problems of me that you may found too, so that eventually the ISP was terminate of the contract with my business. What should I do, should I close my internet shop, and sell out inexpensive of the units PC of mine? oh my good, this is my weakness to run the business such a internet shop through the amid economic competition and my finance.
From here I think, is there any ISP that can provide cheaper rates to revive the love of business by students to do their school work. I would not say the ISP that provides cheap services using usb modem like the picture above, I do not want to promote here! Whatever the usb modem that you use is up to you. The important thing is how you know the stability of the internet connection. I suggest you do not use ISP that has speeds of 7 mbps supposing, but you just have only a few minutes and the rest is request timed out (rto) too much and very long, and finally make your disappointment.
Once you are connected to internet from the isp, open cmd on your pc, and then you typing ping google.com -t -l 1. If you don't want to type, please download this ping.bat ! You see for 1 hour the ping stability. And next day try to do this in the time of traffic congested usually, before you are sure to use that isp. Especially if you use of the usb modem, one of the isp may not as good in different location. If you have sufficient funds you will certainly choose the isp that give you fast and stable of internet connection, and make you satisfaction, but the satisfaction must be paid in kind expenses.
Finally I decided to choose two usb modem of internet connection using the same isp at speeds of up to 512 kbps at a relatively very cheap for me. If you have the stable connection from 2 different ISP would be better yet, let alone have a greater speed. Of course it can make load balancing will be better and satisfy your clients.
Two internet connection using 2 usb modem that shared through pc server in order to get 2 lan of internet connection with two different gateways. And then inserted into the router mikrotik, in here, I use mikrotik Rb 750, as the input are wan1 and wan2 of internet connection of router mikrotik, from here we will apply dual wan load balancing method that we will be equipped with automatic routes failover. To increase the performance of load balancing we must build the external proxy and local dns server. So the internet connection of usb modem that relatively slow, feels like using internet broadband of my isp before, that is enough for 6 clients already.
There are various methods in load balancing, The most commonly used are ECMP (Equal Cost Multi-Path) and PCC (Per Connection Classifier). I think every method has excess and lack, but it is depending on your network, must be try and perceived the effect. For me, load balancing is a method of merging two or more internet connections so that the internet connections from different line will load in balance, according to their capacities. Ok just for beginning as image for you, we look at the basic structure of load balancing that i have build.
It doesn't matter whether you use any usb modem that you trust it and have a good stability. First you need to share of two usb modem into two lan adapter of the pc server. Here I have not found yet, the tools as converter the usb to lan internet connection without using a pc for all kind of ISP of the usb modem, from here i have shared the internet connections via the billing and printer of the pc server, because the pc server in a position that stay alive from my network. But this up to you to manage it. And then you connect to your router, in this case i use mikrotik router Rb 750. I have used the interface 1 as wan1 (default internet source), inteface 2 as ether1 (default lan), and interface 3 as wan2 interface (second internet source). Of course if you use the ISP that does not use usb modem, you can go straight to your router. To be continue ...