[SOLVED] Replace Arris CM820 / Arris DG1670 combo

[jbo007]

For 7+ years I have Time Warner/Spectrum service at a remote office. Nothing fancy, just 100Mbps service I believe but fine for my limited purposes.

Running an Arris CM820 modem and an Arris DG1670 router with coax between the two.
Problem is that even when sitting in the office I can't get to the router admin page for the last six months, maybe a year. I can log in and usually see the first page or two but trying to get deeper, like the port forwarding page all I get is a "please wait" page that never goes away. Power cycling doesn't help.
Not sure if this has to do with having a bunch of port forwarding rules or maybe because I have 25+ "computers" hooked up to my system (computers = security cams, raspberry pi's, a couple of routers on other floors, a fire alarm, as well as one server and the occasional cell phone connection).
If it matters I also have a couple of telephone lines hooked up to the system (for alarm services).

I've been thinking about replacing the whole thing with something simple but more modern where I can actually get back to all off the admin pages.

Any recommendations?

 

[SamirD]

That is an oddball setup. You already have a modem built-into the 1670--why do you have the cm820 at all?

 

[jbo007]

Thanks.
I used to have 4 phone lines and have RJ11 running from one of them (can't recall which one right now) and into modular plugs for a couple of alarm lines that are moving to cellular. Currently only using 1 phone line and soon to be zero phone lines at that location - maybe that is why they stuck in 2 pieces?

(1)After I get rid of the phone lines, can I just replace the CM820 and DF1670 combination with one new Netgear/Motorola/Linksys mid level cable modem and feed them to an off the shelf router that can act as the gateway, handle NAT-ing and port forwarding?
(2)If I see that the dg1670 isn't doing anything regarding the 1 phone line that is still in use, can I just remove it from the system and let another openwrt/dd-wrt router become the gateway, handle port forwarding and other duties on the local subnet?

Sorry about the noob questions, I'm a perl/C/Java programmer who knows just enough about networking to totally destroy my system.

 

[SamirD]

Ah, that makes sense--they had a second modem just for the additional lines.

1. Yep, you should be able to replace the modem with anything on their approved list and be fine.

2. You could, but there wouldn't be an advantage to it other than having to set up something new.

Haha! I know enough about programming to complete fubar my computer, so it goes both ways.