Gigabit/ethernet ports: In/OUT: which way round or does it matter?

[Anonymous user]

Model: Back-UPS RS 1200G
Serial number: 4B1927P08*** (last 2 digits intentionally asterisked out)
Firmware revision: 877.L5.I
Software version: PowerChute Personal Edition 3.1.0

OS: Windows 10 Pro, connected via USB.

(I had a quick search in the forums for anything similar/related but didn't come up with much. Hope I've posted in the correct forum, if not, please feel free for the mods to move to the correct place)

I am interested in the Gigabit ports on the back of my UPS which are labelled In and Out.
I want to use them for ethernet cable with powerline/homeplug.

I'm currently investigating homeplug/powerline (model: TP-Link's WPA8630P) which require an ethernet cable from the homeplug adapter in the electric socket to the router.
There's a diagram in the Quick start guide: https://www.tp-link.com/uk/support/download/tl-wpa8630p-kit/
If there was to be a surge/spike on the house's electricity supply, the surge might pass into the router (which is otherwise protected by a UPS).

On the UPS:

there are two pairs of IN/OUT ports on the rear for phone and ethernet.

https://download.schneider-electric.com/files?p_File_Name=BU%20QS%20990-3889B%20MN01%20EN.pdf&p_Doc_...
has a diagram on the rear ports on page 2 of the pdf

For the Ethernet surge-protected ports, it says "Use an ethernet cable to connect a cable modem to the IN port, and connect a computer to the OUT port."

The parallel situation is the telephone cable surge-protected ports on the other side of the unit. This is more obvious, as the phone line comes _in_ to your house from outside to the IN port, then connect to a modem from the OUT port.
The documentation says: "Connect a telephone cable to the IN port, and connect a modem to the OUT port."

My hunch is to connect the homeplug/powerline ethernet to the IN port (as that is where the threat/surge may come from), and from the OUT port on the UPS to the router (as this would need protecting). This is opposite the documentation.

I've tried switching the two ethernet cables in the IN/OUT ports, and the connectivity is the same both ways (so putting in the ethernet cable connectors the "other" way doesn't seem to affect the connection)

Does it make a difference which way the Gigabit/Ethernet IN/OUT ports are used?
Is one IN/OUT port more protected than the other?

TIA

[BillP · Accepted solution]

The "In" is for the "risky" side, the "Out" is for the side you want to protect.

If you want to protect your modem/router then that gets connected to the out.

-Gavan

[Anonymous user]

Thank you. Very useful and helpful reply.