Using Apple Time Capsule as wifi extender from xfinity modem?

Is this possible?

Unfortunately, you did not indicate whether you planned to "extend" by having the Time Capsule connected permanently with an Ethernet connection back to the xfinity modem/router, or whether you wanted to "extend" by having the Time Capsule connect using wireless......so the best answer that we can give at this time is Yes and No.

Yes, if the Time Capsule will be located where you need more wireless coverage and it will connect permanently back to the xfinity modem/router using a wired Ethernet connection.

No, if you were asking about whether the Time Capsule can wirelessly extend the signal from an xfinity modem/router.

How do I do it?

Please let us know if you are able to consider using a permanent wired Ethernet connection between the xfinity modem/router and Time Capsule.

In general, yes.

But first, the Time Capsule would need to be reset back to factory default settings so that can be reconfigured to work correctly with the xfinity modem/router.

The Ethernet cable would connect from one of the four LAN <--> ports on the xfinity modem/router to the WAN "O" port on the Time Capsule.

The setup will depend on what operating system is installed on your MacBook Pro, so we would need the info if you want more tips on how to set things up. I assume that you know the exact name of the wireless network and password that the xfinity modem/router produces, correct?

Or, did you want the Time Capsule to produce a wireless network that uses a different wireless network name and password?

First test the Ethernet cable that will be connecting down to the basement by temporarily connecting a computer directly to the Ethernet cable. Turn off the WiFi on the computer and make sure that you can get a good Internet connection that way. If you can, then the Time Capsule will work well.

If you cannot get a good Internet connection during your "test", then you will have to get that working first, before you can connect and set up the Time Capsule.

When you are ready, power up the Time Capsule for a few minutes

Then, hold in the reset button on the back of the Time Capsule for 7 to 8 seconds and release

Allow a full minute for the Time Capsule to restart back to a slow, blinking amber light status

Connect the Ethernet cable to the WAN "O" port on the Time Capsule

Click the WiFi menu icon at the top of the MacBook Pro's screen and look for a listing of New AirPort Base Station

Just below that, click directly on Time Capsule

The example below shows an AirPort Extreme as the new base station. You will see Time Capsule on your Mac.

When you click on Time Capsule, that will get the setup "wizard" up and running. It will take few seconds to analyze things and then display a screen that will look similar to this, except that you will see your Time Capsule pictured.

For Network Name.......Type in the exact same wireless network name that the xfinity network is using

For Base Station.......Type is a short simple name that you want to call the Time Capsule

For Password......Type in the exact same password that the xfinity network uses

For Verify......Type in the same password again to confirm

Click Next

The wizard will set everything up for you automatically. When you see the message of Setup Complete, click Done.

Important......power off both the xfinity modem/router and the Time Capsule

Wait a few seconds

Power up the xfinity modem/router and let it run a full minute

Then, power up the Time Capsule and you should be all set

When/If the Time Capsule displays a slow, blinking amber light.....

Open AirPort Utility.....(Finder > Applications > Utilities > AirPort Utility)

Click on the picture of the Time Capsule

Look for an Update button in the smaller window that appears to update the firmware on the Time Capsule