I want to do load balancing with 20 WAN connections, I know the type PCC. What is the best way for the type of load balancing this, thanks
Depend on the requirement, 20 WAN PCC works, if you are using both-address-and-ports approach, this will randomize things the most and in theory give you the most fair allocation of bandwidth, BUT there is also a good chance that it will break certain things like few forums, secure sites, streaming videos. This is because often times a HTTP requests will generate several connections, so there is a chance that some requests may go out a different route than the initial one, and that will break secure web sites. Its good for Downloading via IDM or other download manager as you will be able to utilized maximum bandwidth from all wan’s for multiple downloads.
If users will hit this pcc box directly, then you can avoid having broken links by using src-address approach, but number of users should be sufficient to get proper load balancing among different wan’s.Load balancing using this PCC technique (src-address) will be effective and balanced approach when more and more connections (from clients) that occurred.
I also recommend to use SQUID proxy server along with mikrotik , either parallel or in front or backend , for better response time and it will also increase good browsing experience to users
Also for this number of wan links , you better use some auto fail over topology so if one or more wan links goes down, then it should stop routing requests to failed link(s). There are various scripts and methods available for this purpose. Search the wiki for Netwatch script and fail over route method.
Sorry, but as I understand it, using both addresses means that the connections between two addresses (host+guest) will be kept on the same gateway. You need to use both-addresses without involving the ports. So, no matter how many connections a http will request and how many different ports, those will be kept together on the same gateway (same connection mark).