Orbi has a "debug" feature which will capture every packet that flows through the network and store them in a standard format called "PCAP". There are programs which will display and summarize PCAP files. Wireshark, for example, is available for Windows, Mac, and a number of Linux releases.
Our internet usage is minimal (very little streaming), and we average about 8GB/day of internet. Internal traffic is mostly IP camera FTP's. Of the 495MB internal memory, my RBR50 has about 300MB free so I can capture several hours. It also has a USB port that I stick a 32GB memory stick in for big captures. I just now captured about two hours. I have defined each of the MAC and IP address in Wireshark configuration files so that displays are more "human friendly." Capturing everything means it record a LOT of things I have no interest in, so it is a bit tedious to wade through.
Wireshark will show "conversations" between devices, IP addresses, etc. Number of packets. Number of bytes.
This is not easy, concise, automatic, or attractive. So, what value is it?
One person posted about data usage by device because he had gone over his 1TB monthly limit and the ISP was going to begin charging him. Eventually, he traced the problem to a misconfigured device that was constantly blasting data "to" the internet. If one device is responsible for 100 times more data than any other device, it will pop to the top of the display. So, for idle curiosity this is probably more effort than it is worth. If there is a usage problem, it is something to consider.
