Just keep using your new router to talk with the old landline line.
Just keep using your new router to talk with the old landline line.
I am trying to switch from an old modem router to a new wireless one because it slows down my internet. I wonder if I can connect the new device straight to my existing phone line so that both stay connected? I need to clarify that this setup is "BYO" (bring your own) and involves a TP Link Archer VR600v AC1600 wireless Gigabit Voip ADSL/VDSL Modem Router.
You need to connect your old modem's router directly to a new wireless router instead. If you set up the new one in AP mode while keeping the old router connected, their signals will clash and cause issues (check the manual for more details). When everything is working well on your side, just turn off those Wi-Fi radios if you don't want them still active. This assumes the problem is with the modem's Wi-Fi since the speed over a wired Ethernet connection would be the same as it was before.