Can an Airport Extreme be used as a Wireless Access Point for a Comcast Modem/Router Combo?

bareyb wrote:

Thank you that's very helpful. What I might do instead is remove the Airport Extreme and put the Time Capsule in it's place. I'm upgrading the modem so I can get 500 mbps. Do you happen to know if a Time Capsule/Router (latest version, tower) is capable of sustained 500 mbps wireless speeds?

This is a bit more difficult to answer.

If you are buying a pure modem, no router then using the tower model TC or AE as router, you will have issues pushing 500mbps period.

It is just not that fast as a NAT router. You should get close though.. 400mbps is not unreasonable.

What gets confusing is that internet is swapping to IPv6, and most of the cable suppliers in the US are already on IPv6.

It is much more efficient without needing NAT in the router so you can achieve your full 500mbps as long as the site is fully IPv6 you are connected to. So in tests it can vary a lot depending on particular situation.

If you are buying a modem router suited to your new 500mbps connection that eliminates the issue of NAT and the Apple router is setup as a dumb AP and switch (plus backup for the TC). In this scenario the limiting factor is your cable speed as long as you use gigabit ethernet all the way.

Wireless is kinda tricky.

If you are close to the TC using a full AC1300 capable wireless card, your throughput should come out close to 500Mbps.

Here is an example.

I have a connection to an Asus high end wireless router. The Mac has a full AC1300 capable wireless card.

As you can see in the list my Tx link speed is 1053Mbps.

The Asus is great because it shows me more info.. the link speed at its end. Note that speeds don't match. This is showing Tx at 1300 and Rx 1170 but it bounces around a bit.

Now if I connect this wireless to a Gen 5 tower model Time Capsule.

And this is with a lot of messing around to get link speed up.

I get much lower speed. 878Mbps.

To get actual throughput on wireless you need to divide by 2.. and hope for the best. I would get around 400Mbps (internet here is not that fast to test) even with the highest speed I would be pushing to get 500Mbps. Wireless in the end is just not quite there.

The more devices that share the wireless the less efficient it is and the more it will slow down.. so if you really want your full speed buy ethernet adapter for your device.. or live with what will still be very good speed if not the max.

Yes. That is fine. You must have it connected by ethernet which is how you have it running.

You will need to change the wireless name (SSID) on new modem router or AE to keep roaming.

You can also plug the TC into the system also in bridge to use for backups if you wish.

If you have issues later on with the AE disappearing from the network post back. A lot of routers do not handle bonjour very well.

I'm wondering if I can remove the Time Capsule and use the new Comcast Modem Router in it's place and continue to use the Airport Extreme in the Office as an Access Point (in Bridge mode) exactly like I am now, only connected directly (via ethernet) to the Comcast Router instead of to another Apple Product.

Sure. You will need to decide whether to rename the WiFi network on the modem/router the same as the WiFi network on the AirPort Extreme......or.....rename the WiFi network on the AirPort Extreme to be the same as the name of the modem/router WiFi network.

Since your WiFi devices are likely already programmed to join the Apple network, you can probably save yourself some time if you can simply rename the wireless network and WiFi password on the modem/router to be the same as the AirPort Extreme.

Are you renting? You can pick up and own a new DOCSIS modem for $60-200. Honestly, the 60-80 range for a modem is going to be good. But there are used ones that are still fine (Docsis 3) for $20 used. I had one I had that I had for my mom, barely used, I wanted to unload… but nobody wanted to pay me even $20 for it. So, I donated it. But there are many for sale all over now that are no different than that $60 modem.

Call Comcast and tell them you have bought one. Make sure it is on the Comcast approved modem list before you buy one. They switch it over.

Then return the Comcast junk modem to them.

Plug in the Extreme to the back of the modem and, away you go.

I'm getting 1170 Mbps Wi-Fi on 2017 Retina 27 inch from Extreme 802.11 a/b/g/n/ac with 22 devices on Wi-Fi. Actually, normally 30+ but some are off. The only devices I know for sure pulling from it was an iPhone playing HD stream and some typical mysterious MacOS background processing. My broadband service is 50 Mbps DOCSIS but I am getting 70 down and 6 up. That was tested on DSL Reports (generally considered the most accurate) but confirmed with Ookla and Speakeasy. (I never trust any provider's test.)

I'm getting 1170 Mbps Wi-Fi

Sounds like this is a Transmit Rate number, which always looks impressive, but does not tell you what is actually happening. Actual throughput is usually about a third to half of the Tx Rate.

As LaPastenague will explain, the only way to really know what is happening on your network is copy a file....say 1 GB or so..... from one device to another and note the exact time that it takes for the process to complete.

When I run this check, my Mac.....which shows a1100 to 1300 Mbps connection.....the actual speed checks out a little over 350 Mbps with about 15 other devices on the network. Most are actively connected to the Internet, but not downloading anything at the time.

My broadband service is 50 Mbps DOCSIS but I am getting 70 down and 6 up.

You will have no issues with the slower speed. The ratio of wireless speed to internet speed means you can easily saturate your connection. The problem will come if you go to 500Mbps.

Remember with most devices that still use N wireless they are limited to much slower link speed at 2.4ghz of 150Mbps or in the case of the later cards that might peak out at 217Mbps. For 5ghz the numbers are 300 and 450Mbps. So none of those devices can ever reach your new high speed 500Mbps. (Simply halve all those link speeds to get the best possible speed).

As Bob pointed out the reality.. harsh cold environment is that wireless is subject to lots of efficiency and sharing problems. His best speed in real world with lots of devices connected of around 350Mbps is what I would expect. As soon as you start sharing wireless with lots of other devices.. even if they are not doing anything.. they still require a time slice.

Also I would just add that 30+ devices is over-saturation for a wireless point if you really want high speed. You are going to do better splitting the load over two AP. That is why ordering a modem router from your ISP for the new setup could be well worth it as the new router gives you more wireless coverage.. or think about using a better wireless router or AP system. Or split into fast and slow networks.. using different wireless names.. so that slow items are not restricting faster ones.

Mind you the internet is often no faster.. so you still need to balance cost vs speed. Most things I do today on 100Mbps fibre are no better than what I did on 4Mbps ADSL. Web pages load at about the same speed mostly, emails go at the same speed. It is only when you start busy and multiple video streams that you really appreciate having more. And going above 50Mbps is hitting law of diminishing returns.

Sounds like a plan. Good luck!