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Need to switch landline service to Cox. My modem has only one port (ethernet) Do I use a port on the router to plug in the landline phone?
You need a phone modem(eMTA) to use Cox phone service. One is provided as a free lease to you when you start service. The typical model given is the Arris TM3402. It has a phone connection(RJ11) and ethernet(RJ45) for internet. It only provides one ethernet connection, so you need a router for more ethernet and Wifi. If you want wifi built in, you can rent($) a Technicolor CGM4141.