Region : Netherlands

Model : TL-SG1016DE

Hardware Version : V1

Firmware Version : current

ISP :

I have a beginners question.
I have the TG1016DE and did a line check, one of the lines gave the result "open", which is not explained further in the manual.
And as I am a starter on this subject I'd like to know what it means?
Is this the cable that leads to my main router? but the cable length doesn't match (should be about 6 metres and not 16)
I see all other cables report "normal" as their status.....
Or is it the cable that leads to my second router in the attic that I have set as an acces point? Otherwise I'm clueless.
And since I'd like to set up my network to be secure (kids groing up bringing free virusses, and wanting my pictures, and work to stay safe.....) I'd like to know a bit more than that it is a result as such.....
Thanks in advance for explaining..... ;-)