Re: Nighthawk X4S 7800 How do I connect a landline phone? The back has only 4 ethernet ports, no au
Check the model number on the back of your device. If it is truly a cable modem/router, the model number should start with a C. Maybe C7800 in your case.
Who is your ISP? Does your ISP support a land line connection as part of your internet service?
If yes, you are looking for an EMTA (Embedded Multimedia Terminal Adapter). Sometimes these are a part of your modem/gateway and sometimes not. The cable modem/router devices that include an EMTA are usually provided (rented for a monthly fee) by your internet service provider.
Is there a way to connect a landline phone to this Nighthawk?/
I have 4 ethernet ports available, no audio port
What are you trying to achieve?
If you want to plug a standard phone into a cable modem/router you need a "V" model. Something like the C7100V, for example.
AC7800 is not a reliable guide to model number. Many devices come with an AC tag, but it is essentially a label that Netgear, and other brands, attach to hardware to describe wifi speeds. At least it would be if there were such a thing as AC7800. But I can't find any.
The C7100V is AC1900.
Look at the label on the device for the model number.
It isn't clear what your modem/router is, but at a quick glance there is no Netgear "AC7800" cable modem router that supports voice.
You might get more help, and find earlier questions and answers specific to your device, in the appropriate section for your hardware. That's probably here:
