50ohm resistor for all IC pins?

I'm building a powerline modem using Belfuse's powerline module:

I've requested for reference design and they say no reference design are available.

My question: I have realized with the reference design of my ethernet transceiver that most of the pins (unless specifically stated) have a 50ohm resistor (i'm assuming its a terminating resistor?).

Since without a reference design, i'm guessing i just connect the pins of the powerline module directly to the corresponding pins at my ethernet transceiver. My question is, do i have to place any resistors btwn these connections too? Is there like a conventional rule of thumb etc when dealing with these kind of situations?