nighthawk rax40 device data usage

Long story short: can you track individual device data usage with the RAX40? Is there third party software I can use that is compatible.

Hello, I have hit the Xfinity Data cap in the last two months, and it looks like I about to hit the third, the last two months were free, but now I am going to get hit with overages, we went over 1TB consecutively over the holidays. 

I have a family of five, so we have a lot of devices, two PCs, five ipads, an xbox, three phones, couple of smart tvs, etc. So I am not surprised we are hitting the data caps, but I would like to try to track which individual device is sucking down the sweet sweet data, I have the traffic meter turned on but that only confirms the total, not which kid I need to yell at for using all the data.

I am resigned to going to Comcast and going with the unlimited plan, but am loath to shill it out extra money to find out one single device is the cause. 

I appreciate the help

Mark