I’m using my own equipment with Comcast and have been doing so for several years. I also checked Comcast’s page for approved equipment, to ensure compatibility, but if all you need is Internet access (no voice or home security services), then you can probably ignore it and get anything that is DOCSIS 3.0 or 3.1 compatible.
In my case (remember, this was several years ago), I bought a Zoom model 5352 modem/router combo. This unit is no longer made, but for comparison purposes, it features:
- DOCSIS 3.0
- 8 downlink channels (max 343 Mbps)
- 4 uplink channels (max 123 Mbps)
- 802.11n Wi-Fi
It worked well for quite some time. Over the years, the Wi-Fi started getting flaky, so I put it into bridge mode (converting it to a dumb cable modem) and attached a Linksys MR8300 router for all my routing, gateway and Wi-Fi needs. The combination has worked very well for my Internet service (100 Mbps downlink, 6 Mbps uplink).
I would recommend, in general, to not get a combination modem/router, but get separate devices. Here’s why:
- You probably won’t be replacing them on the same schedule. If they’re separate devices, you can upgrade the parts that need upgrading and keep the parts that don’t.
- There’s a much much greater choice of routers than there are modems. Especially if you want to stick with a modem from Comcast’s list. By keeping them separate, you can use almost any router that exists.
- This is probably the most important one. For some reason (I assume legal), you can not install your own firmware upgrades into a cable modem - your service provider (Comcast, in this case) is responsible for pushing updates into it. If your modem includes a router, then you can’t upgrade the router firmware either. It’s been my experience that Comcast really doesn’t care about pushing out firmware updates, which means it will end up being pretty old, buggy and probably full of security holes. You can’t do anything about the modem firmware, but if the router is a separate device, you can keep it up to date on your own.
If I were to recommend something today, I would recommend doing what you’re doing. Buy separate modems and routers. Buy a modem off of Comcast’s list of models recommended for your level of service.
In order to support future service upgrades, I’d pay a bit extra to get a high-end modem. Today, this means DOCSIS 3.1 support, with 32 downlink channels and 8 uplink channels. These will support up to gigabit speeds. When I visit Comcast’s page, they list the following modem-only (non-router) devices with those features:
- Arris T25. About $200 at Amazon. Includes support for digital voice service, should you want it in the future.
- Arris SB8200. About $150 at Amazon. No support for voice service
- Motorola MB8600. About $160 at Amazon. No voice service.
- Netgear CM1200. About $200 at Amazon. This model claims it can go up to 2Gbps if/when Comcast should start offering such service. No voice service.
- Netgear CM1150V. About $240 at Amazon. This looks like the CM1200 plus voice service capability
- Netgear CM1100. I can’t find this model on Amazon. No voice service.
- Netgear CM1000v2. I can’t find this model on Amazon. No voice service.
- Netgear CM1000-1AZNAS. About $160 at Amazon. No voice service
- Netgear CM1000. I can’t find this on Amazon. I don’t know if it’s the same as the CM1000-1AZNAS
I can’t recommend any of these because I’ve never used any of them. I would do some web searching for product reviews, eliminate those that have bad reliability and buy the least expensive model from what’s left.
As for your installer being unable to set up third-party modems, that just proves he doesn’t know what he’s doing. It’s trivially simple.
Plug in the modem and attach a computer to it. Either connect directly (making sure your computer is running firewall software!) or via your router. Go visit a web page (I suggest Comcast’s home page).
You’ll find that every page you visit redirects to a Comcast sign-on page (much like hotel Internet service). Log on using your Comcast user ID and password. Comcast will authenticate you and automatically register your modem with the service. They will then (probably) push firmware and configuration data into the modem. Let it do this. It will probably take a few minutes. Once completed, the modem will reboot and you’ll be on-line.
Now go attach your router and configure it the way you want in order to let your whole LAN access the Internet.