anon86290's profile

Valued Contributor


328 Messages

Mon, Nov 23, 2020 8:00 PM

Activating Gateway Where There's no Cellular Signal

My daughter just signed up for internet, TV, and voice.  She will be renting a Comcast gateway with voice.  She has AT&T cellular.

She'll be moving to an area where there is Comcast, but cellular service is iffy to non-existent.  The instructions on how to activate her Comcast gateway say to download the app from the app store.  Can she download it when she is in my area where cellular signal is fine, and then use the app at her new location?  That is, what does the app communicate with, the gateway, or is it needed to communicate with Comcast, which it won't be able to do since there's no cellular signal where she is setting up the gateway.

What does she do?



Accepted Solution




87.1K Messages

7 m ago

The app is not needed.


Have her connect it to the coax line and power it up. Let it fully sync up with the system ("DS, "US", and the "Online" lights are steadily lit). Connect a computer to it and open up a browser. You *may* see their "Walled Garden" modem self registration page. If so, follow the screen prompts. Have your mobile telephone number, your Xfinity username and password or the account number and telephone number associated with your Comcast account handy.

If not, try calling 1-855-652-3446. That is their device activation line.

If that doesn't work for her, she can call 1-800-comcast and tell a rep that you would like to have a new modem provisioned for service. Have the RF / CM / HFC MAC address and the serial number of it handy when you call.

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Diamond Problem Solver


25.9K Messages

7 m ago

It’s to communicate with Comcast, when the modem is connected properly and ready to be activated

Valued Contributor


328 Messages

7 m ago

Great information!  Thanks.  I'll print out and have her take with her.  I will be going up to her new place two days after her.  Today, she is still here, and there's a full service Comcast store within five miles.  If she picks up equipment here, can they activate it over the counter, or does it have to be connected to the Comcast coax at her new place, or is all they can do over the counter is register the equipment?


Also, I see you say to have her mobile phone number ready, or any other means of identification.  I assume her mobile phone number would be just for identification, and that's not the phone number Comcast would think is her VOIP number.   Comcast assigned her a VOIP number yesterday when she signed up online here.  So when she talks over VOIP, it will be with the VOIP number.  I've never set up VOIP, but my mother-in-law has Comcast VOIP, and she just plugs her landline (POTS) RJ-11 cord into the wall outlet.  I haven't been able to find the instructions for the Xfinity gateway with voice, but I suspect that there's an RJ-11 port that my daughter would plug the telephone line of a (wireless) base set into, or if there is a telephone wall outlet, she'd connect that to the RJ-11 port of the gateway, and all other phones to any other wall outlets, if available.   Where she's moving to, we just found out, the seller had Comcast internet, TV, and voice.


Just curious...I don't think there's a way to have a cellular phone number at the same time be assigned to VOIP, because if someone calls the cellular number, the cell provider sends the signal over the mobile network, and not the internet.  I guess the question is can two devices, a cell phone and a VOIP device, have the same phone number.  Seems to me, no.


Just read that the gateway does have an RJ-11 port, and I don't need the home to be wired for telephone.  I just plug into the gateway's port.

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