Time Capsule or ISPs modem/router as primary

The next question would be whether you prefer to have the Time Capsule act as the main router for the network, or have the Arris handle the network chores.

If your Time Capsule has been serving as the main router on the network in the past, there should not be anything that you need to change on configuration settings of the Time Capsule or other AirPorts on the network.

So, you would power off the Time Capsule and other AirPorts and connect your computer directly to the Arris product to set it up in Bridge Mode. Once that is accomplished, you would power off the Arris product and connect the Time Capsule back up to the Arris modem.

Start up the Arris and let it run for a minute, then start up the Time Capsule and let it run for a minute, then start up other routers and finally other devices one at a time until the entire network is back up.

Not sure if this important to you or not, but when the Time Capsule is configured as the main router on the network, your Internet speed on the network is going to top out in the 300-350 Mbps range. When the Time Capsule is set up in Bridge Mode, it should be able to handle speeds in the 800-900 Mbps range.

The potential downside to setting up the Arris in Bridge Mode is that if you have a problem with the Time Capsule connecting to the Internet, that the ISP will blame the Time Capsule. If you ask Apple Support, they will likely blame the Arris "modem".

I've been through episodes like this in the past. That is why I will not use a modem/router or gateway like the Arris product and try to modify it to do something else. If I want my AirPort Extreme to act as the main router....I do... I use a simple modem......the kind that has only one Ethernet port.....to connect to the ISP.

If you have the option to use a simple modem with your ISP rather than a modem/router or gateway, that would really simplify things. The simple things always seem to work better and more reliably than other more complicated setups.

I think you already know the answer to this one.

The optimal setup in terms of potential speed would be to use the Arris modem/router or gateway "as is" and set up the Time Capsule in Bridge Mode, which Apple calls "Off (Bridge Mode)" The other AirPorts on the network are already set up in Bridge Mode, so the only change that would normally be needed would be to change the Network Router Mode settings on the Time Capsule from DHCP and NAT to Off (Bridge Mode).

The Arris modem/router is also going to provide another separate Wi-Fi network, so if you want to continue to use Time Capsule and other AirPorts Wi-Fi, you can simply not use the Arris Wi-Fi signal. There is also probably a setting to turn off the Wi-Fi on the Arris if you don't want to have an additional Wi-Fi signal in the air.

So, in my current setup where I have the Arris as one network and the TC (and AirPort "extenders") as another network, there's no downside to those two routers being in close proximity to one another?

That's correct.

Is there no performance issues (assuming they navigate to good channels)?

No issues, since this is the correct setup when you have two devices in close proximity both producing a Wi-Fi signal.

I think I would like that step-by-step on how to set it up as one single network where the Arris is in one room, the TC in another and they're connected by an ethernet cable

You have done a good job setting things up, so I don't think you really need step by step.

To set things up this way, you would first power off the AirPort Extreme that is now extending the Wi-Fi signal that the Time Capsule is providing.

The next step would be to simply change the name and password of the Wi-Fi network that the Time Capsule is now providing to exactly match the same wireless network name and password that the Arris modem/router is producing.

Then, you would perform a Hard Reset on the AirPort Extreme to erase the current network settings, temporarily move it close to the Time Capsule and then set up the AirPort Extreme to extend the Wi-Fi signal from the Time Capsule. When the AirPort Extreme displays a green light, move it back to the area where it will reside.

Note.....it is very important that the AirPort Extreme receives a much stronger signal from the Time Capsule than it receives from the Arris modem/router to allow the AirPort Extreme to extend correctly.

If you are willing to experiment, you could probably get away with having the Arris and Time Capsule in the same room, as long as they are not side by side or very close together. If you could use a 15-25 foot Ethernet cable to locate the Time Capsule at the other side of the room or along another wall, you will probably be OK.

The real reason that you don't want two devices both producing the same wireless network when they located close together is that this will confuse other Wi-Fi devices like your laptops, phones, etc because they won't be able to clearly detect the stronger signal between the Arris and the Time Capsule.

It would be like an FM radio station setting up two tall antennas side by side to both broadcast the same radio signal. Not only would this confuse car radios that are connected to the radio station, there would be no gain in the actual signal strength of the signal. It would make much more sense to set up the second radio antenna 20-30 miles away from the main antenna because the radio station would have much more reach that way.

Good luck!

You are going to have two separate Wi-Fi networks. One network is the Arris Wi-Fi and other network is the Time Capsule and other AirPort(s) Wi-Fi network.

My suggestion was to either ignore the Arris Wi-Fi and not use it or turn it off. If you had elected to set up the Arris in Bridge Mode it would not have provided a Wi-Fi signal at all.

If you want the Time Capsule and other AirPort(s) to use the same Wi-Fi network as the Arris, that would mean that you must reset the Time Capsule and AirPort(s) back to default settings and then set them up again to use the same wireless network name and password that the Arris router is using. That's a major undertaking, but it can be done.

Unfortunately, you will have to set up all of your Wi-Fi devices.....computers, iPhones, iPads, printer, etc....to connect to the "new" Arris network.

One note of caution though. You would not want to have the Arris router and Time Capsule both providing the same wireless network if they will be in close proximity to each other. That would create interference effects between the two devices. The Time Capsule needs to be located at least a room or two away from the Arris router if you want to have the Arris , Time Capsule and other AirPort all using the same wireless network name.

If all of your Wi-Fi devices are 5 GHz capable, then you can set up both the Arris and TC/AirPort for 5 GHz only. I'm not familiar with the settings on the Arris modem/router, but you can simply turn off the 2.4 GHz network on the TC/AirPorts and have them broadcast 5 GHz only.

So the setting in Airport Utility would be Wireless Tab > Wireless Network Options > 2.4 GHz Off to set up the TC/AirPorts for 5 GHz only.

The Time Capsule and AirPort cannot be wireless extenders for the Arris because they cannot connect to the Arris wireless network.

The AirPort can be a wireless extender for the Time Capsule though.

I'll provide you with a step by step setup for the Time Capsule and AirPort Extreme, but everything will depend on whether the Time Capsule can be located at least a room or two away from the Arris router.....and....connect back to the Arris modem/router permanent wired Ethernet cable connection.

If it can, I'll tell you how to have only one wireless network that uses the same name for the Arris, Time Capsule and AirPort. I think you can easily understand why this would be the simplest solution.

But.....if you cannot locate the Time Capsule at least a room away from the Arris modem/router and connect the Time Capsule back to the Arris modem/router using a permanent wired Ethernet cable connection, then we will have to set up two different wireless networks.

One network will be provided by the Arris modem/router and the other by the Time Capsule and AirPort Extreme. In that case, my suggestion is to simply ignore the Arris wireless network and use the Time Capsule / AirPort network because it will provide much wider coverage for Wi-Fi.

Or, you could designate the Arris Wi-Fi network as a guest network if you don't want to give guests the wireless password for the Time Capsule / AirPort Wi-Fi network.

The Time Capsule cannot connect to the Arris network using a wireless signal. The Time Capsule must connect to a modem or any 3rd party router using a permanent wired Ethernet cable connection.

Please re-read my post above......which Apple recommended......that mentions that you would not want to have the Arris modem/router and the Time Capsule both producing the same network if they are going to be located close together. The Time Capsule needs to be located at least a room or two away from the Arris modem/router.

If the Time Capsule must be located close the Arris modem/router, then you need to set up the Arris to produce one Wi-Fi network and the Time Capsule / AirPort Extreme to produce another separate network, so you will have two networks, as I advised in the Apple Recommened post above. Just ignore the Arris Wi-Fi network since the Time Capsule and and AirPort Extreme will provide much wider coverage.

I guess the first question here would be.......before we go any further.......will your ISP support the Arris TG3452 if it is configured to operate in Bridge Mode? Or will you be basically be "on your own" if you change the default set up of the Arris product?