@Tivoli 

Unfortunately R470T+ may not meet your requirements. It cannot set the policy based on ping delay. 

Its linkbackup function is based on online detection. If primary WAN go offline, the data will go to backup WAN. If primary WAN recover and become online, the data will go back to primary WAN.

@Andone 

Thanks for you reply Andone. Ok, I thought so that R470T+ might not give this kind of solution to my problem..

Maybe I will try to solve the problem the other way around in a more "primitive" way. Since usually when quality of internet connection lowers, i.e. ping time raises, usually at the same time speed is lower. So I am thinking I will observe values of both at different situations in order to create a rule of thumb - e.g. when download speed is bellow 3.5Mbps or upload lower than 650Kbps to switch from WAN1 to WAN2. 

However, just out of curiosity, how online detection is done? I thought it is done through a ping timeout and packets answer from the server. R470t would be a more uesefull piece of equipment if we had the option to control when the wan should be considered online or offline based on ping results. 

Anyway, thanks once again for your reply! 

Cheers!

Vangelis

EDIT: What I have written above can't be accomplished with R470t. The only way I see is the completely manual way. I.e. when I experience large ping and/or lot of jitter to switch primary-backup WAN  

@Tivoli 

Online detection contains Ping and DNS lookup. You can use one of them or both of them. If the router cannot ping the specific IP address or cannot resolve domain name from DNS server, it will think that WAN is offline and transfer the traffic to other WAN. (Please note that this is only applied in Link backup function.)