A picture is worth a thousand words
The blue device on the left is "ZXDSL 831 Series Modem Router". I was calling it modem.
The white device on the left, labelled "BayLan" is what I am calling hub and it is "5-P Ethernet hub" (model# EH5T)
The blue cable in the hub is going to the PC, the white one to the laptop and the gray is going to the modem router
Now, I guess, everything is clear. Thanks