network setup

Unfortunately, you have provided so little information that it would be difficult to tell you what network setup would be best for your situation,

To help us, we will need some additional details, like:

• The make & model of your modem and 16-port switch?
• The exact model of your Time Capsule (TC)?
• Will all of these devices be interconnected by Ethernet or by wireless or both?
• What are your overall networking goals for this equipment?

If 1 Gbps is your goal throughout, then your first bottleneck is going to be your Time Capsule. That's because when it is performing as a router, the throughput speeds through it are going to be more like 450-500 Mbps. Actually, very few routers will provide you with a full Gigabit. Remember the TC is about a 6+ year old design. Only the very latest routers today could potentially get you closer to a Gigabit. If that is an important requirement for you, then you should replace the TC with something from Netgear, Asus, or Synology.

I am assuming that your Cisco switch is a Gigabit switch as well. If it is not, then that should be replaced as well. Otherwise, your AirPort Extreme does include Gigabit ports unless it is a 1st generation model.

Bottom line? If you want Gigabit throughout, you will at least need to replace the TC with a newer router. Regardless of which router you use, your local area network should already be capable of near Gigabit speeds via all wired connection and roughly half that for wireless ones based on the equipment you already have.

Here’s a relatively similar configuration...

Modem to a gigabit-capable gateway-firewall-router box such as a ZyXEL ZYWALL USG series. That’s your network perimeter, your security, etc.

From the firewall, wired to a gigabit switch and preferably to switch with Power over Ethernet (PoE) support.

From the switch, copper wiring to the minimal-necessary number of access points (APs).

The APs preferably configured with coordinated frequencies assigned in 5 GHz. Start out of 2.4 GHz, particularly if you want speed.

The Apple Wi-Fi gear is old and slow, and Apple has gotten out of the Wi-Fi business.

Ubiquiti does well with APs such as the UniFi AP AC Pro series, and coverage and performance of that gear is well above that of the Apple Wi-Fi gear, from what I’ve worked with. I’ve replaced several Apple Wi-Fi devices with one UniFi AP AC Pro in one configuration, with equivalent Wi-Fi coverage.

The UniFi AP AC Pro is rated to peak at 1.3 gigabits throughput, but you’ll probably get less than that.

If the current switch is not PoE-capable, you’ll need to use power injectors with your Ubiquiti APs, or for similar AP products, or somehow get power to the APs otherwise. PoE makes mounting more flexible, as you only have to get one wire to the AP, and not two.

The Time Capsule can be re-configured as a network-attached storage (NAS) device, with Wi-Fi disabled, and used with Time Machine. (That’s not officially supported by Apple, but that is working in configurations I’m aware of.) Synology makes nice NAS boxes, and those are supported as targets for Time Machine.

If there’s the budget for it, there are some very nice structured wiring systems that can be implemented. The Leviton stuff wires very nicely. That allows running gigabit or ten gigabit copper, coax, whatever. Whatever you choose for wiring if you follow this path, over-rate it and drag some extra. Most of the cost here is the installation and setup, and the incremental costs of dragging more wiring and/or dragging higher-rated wiring is marginal, as you can be using this wiring for longer than you might expect, and for more. And having spare wiring is handy when one pair gets chewed by a critter, or corrodes.

ps: If your basement is even remotely damp, use gel-filled burial-grade network wiring for any wiring runs there.

I'm assuming with that hardware

If you do not want to get a new router, then you setup

Modem -> Time Capsule -> 16-port switch -> individual ethernet devices

Individual ethernet devices talk to each other via the switch as fast as the switch can move the data.

Talking to Comcast will be limited by what the Time Capsule can do.

If you get a new router, then you do

Modem -> router -> 16-port switch -> individual ethernet devices

\__> Time Capsule in "Bridge Mode" so it is just another device on the network, but doing backup services

The Time Capsule in "Bridge Mode" can also be hung off the 16-Port switch.

The Time Capsule can still provide WiFi services, or you can turn off the Time Capsule radios and just use it as a backup device. This is what my Sister did when she got a mesh WiFi network and no longer wanted to use her Time Capsule as a router nor as a WiFi base stations. So it is in bridge mode with the radios off, but still doing Time Machine backups for her laptop.

No. You can put it into Bridge Mode and from there it can just be a backup device, or if you have a need to extend your network, you can move the Time Capsule to another location in your home that is serviced by Ethernet, and set it up there with the same SSID and password as your main WiFi router.

But if the router you get to replace the Time Capsule is good enough, then just disable the Time Capsule radios along with putting it into Bridge mode.

Google "tme capsule bridge mode" and you will find lots of information about putting your Time Capsule in Bridge mode.