Line modes… Most modern DECT 6.0 phones have this buried deep in their internal phone system menu. The factory-default setting can affect your phone’s reliability on numerous levels. But what is line mode, and how does it affect me?According to a support phone call I had with Panasonic, technical quality is affected by the line modes A and B. When I asked, I was hard pressed to a get a firm technical answer as to how or why there would be a line mode A and B. The support representative wanted to keep it simple by saying it affects sound quality — that sometimes a cord or line sounds staticky. Changing the line mode can make a difference. So I explained that most people want the call quality to be as clear as possible, so merely saying it affects call quality doesn’t really answer the technical question as to why there would even be a line mode A or B.
If you don’t want to learn more about the technical aspects and you just want to “get that blessed phone working”, suffice it to say try both settings and see which one works best for you. Under most circumstances, it is suggested to leave on “Line Mode B”. The below images show how I navigated to the correct setting for my phone.
For the rest of us, let’s carry on.
According to one on-line source for a university PBX system, line mode may have something to do with power supplementation. If your phone system is low voltage (like magicJack) you probably should use mode B. If your house has a Network Interface Device outside your house where you can plug in a trimline phone without a any power and the phone works, you probably have a POTS line or “Plain Old Telephone System” line. If your phone is connected to router perhaps a UVerse modem/router then you are certainly not using a POTS line.
According to another Panasonic source, if you cannot see “Line In Use” when someone else is using one of the other handsets configured to the use same base set, it might help to change the line mode to the alternate setting.
The Ringer Equivalency Number (REN) ends with a B for almost all new model phones, Panasonic or otherwise, so it seems very likely that line mode “B” is somehow integrated or connected with the B at the end of the REN.
While my phone call with Panasonic was not very useful, I found these helpful links.