Home Security System Drops Internet Connection

I'm not sure what security system you're using. ADP? SimpliSafe? I have the Arcadyan KVD21 5G gateway and I use SimpliSafe. It connects and maintains its connection perfectly to my T-Mobile gateway. In fact, T-Mobile is the default connection provider for SimpliSafe out of the box.

When you say 2 GHz, do you really mean 2.4 GHz?

I'd try creating a new 2.4 GHz-only network on your T-Mobile gateway with only WPA/WPA2 security. That usually fixes this type of problem. Use the phone app to create your new network, and make sure that Hidden is turned OFF. Leave all of your other devices, which appear to be working, connected to your default network and connect your security system to your new 2.4 GHz network.

Good luck!

I'd still try creating a new network as I described above. There is, of course, a chance that the same behavior will occur, but there is no cost to trying this potential solution and no more than 3-4 minutes of your time.

Good luck!

A static address is easy! There are two ways to do it. First, if you can get the 2Gig to connect, find out the IP that it's been assigned by the gateway. Then go to the 2G device and reconfigure its network settings. Enter the same IP as the gateway assigned, with 192.168.12.1 as the router and 225.225.255.0 as your mask.

If you can't figure out what IP is being handed out by T-Mobile, use any number under 100 for the fourth quadrant, e.g. 192.168.12.4 using the same parameters for the router and mask.

Lastly, you might want to check the DNS settings on the 2G, if it has any. It's suspicious to me that it gets an address from the gateway and then drops it. It could be that the 2G has its own DNS built in and it's pointing to something that causes it to disconnect.