The questions are coming from the point of view that you're connecting the TP-Link system directly to your ISP feed which would be directly to some sort of modem. Since you're connecting to the T-Mobile cellular gateway, I'm going to say Dynamic IP would work; assuming you're connecting the WAN/Internet port of the gateway TP-Link device to the T-Mobile gateway. In this setup, any IP address management for your wireless devices connected to the TP-Link wireless system would be done by the TP-Link system. The only drawback is that if you need to set up any port forwarding, you have a double NAT situation. While double NAT is not ideal, it's not the end of the world. You can still get port forwarding to work the same as a single NAT. Just requires some additional configuration and understanding on what port forwarding is doing. The other thing you have to ensure is that the T-Mobile gateway is not handing out IP addresses on the same subnet as what the TP-Link is doing for LAN/WLAN connected devices.

 

thanks. i will need to connect one of the nodes to gateway with ethernet cable, gateway has two ethernet ports in the back. each node also offers 2 ethernet ports. Dynamic IP would be my guess,too. I have an option to use that first node (attached to gateway)as a router, or use all 3 as access points. The concern is if two routers (gateway and that first router) will cause wireless interference. Some are saying you can turn off wifi on router and use a dedicated router, and some insist that not possible. Confusing.
what is your recommendation? Just use mesh nodes as access points?

 

Miracles happen! I tried to call t-mobile customer service and waited only 10 minutes.
The rep said it uses Dynamic IP.
I don't know what port forwarding means. I need some internet search. Basically, I want the signal coming from gateway to mesh units not degrade too much. I am thinking if I connect my laptop in my basement to one satellite with ethernet cable I will get a better download speed with big files.

 

Yes. Turn off the wireless function on the T-Mobile gateway. The TP-Link will provide better overall wireless performance.

Port forwarding is essentially punching a hole in your firewall to allow inbound network traffic from the Internet. This is commonly needed when you do online gaming.

You indicated there is an option to use the TP-Link as only a mesh wireless AP system. This would be preferable as it removes the router/firewall function of the TP-Link and hands that off to the T-Mobile gateway. This simplifies configuration and management of your network.

 

Yes Deco S4 manual gives both options. Router capability and access point.
Here's my question. When I set up mesh system, should I enter the same network name and password (that I am currently using with gateway)?
Would Deco units would accept the same information? Of course, I will select 'Access point' during setup.

 

I'm assuming you're referring to what you've configured on the T-Mobile for wireless access. If so, yes. This will make it simple for you to migrate over to the TP-Link system where you don't have to go through each wireless device to enter in something new. But remember to shut off the wireless function of the T-Mobile gateway.

 

Let me see If I understand you clearly. I am an old geezer who is not at your level. (Liz, you are an exception!!)
If I keep the same gateway network name and password and use the mesh system as access point why is it necessary to disable wifi on gateway? The first node (mesh unit) is not working as a router. (I realize a lot of features that mesh system offer will be disabled, But, I will never need them for my needs.)
I am assuming that all the current IP addresses for about 19 devices I currently use will stay the same and mesh will simply give me a better wifi coverage all over the house, which has 3 floors including basement and about 2700 square feet.
The picture shows the options for Deco S4 operating mode.

 

You have to be specific on which gateway you're referring to. I've been very specific on which gateway I am discussing in my replies above.

I highly doubt the Deco that is functioning in router mode would have its wireless functionality disabled. If so, it's a very poor design. When I've mentioned turning off the wireless function of the gateway it's been consistently in reference to the T-Mobile gateway. Having the T-Mobile gateway broadcasting a wireless network is bad in two ways. First, if you leave the T-Mobile as is, you're going to have roaming and association issues with your wireless devices if you also set up the Deco to use the same SSID and passphrase. Second, with the T-Mobile gateway broadcasting a wireless network even if you use a different SSID for the Deco will just add to the potential background noise that can interfere with the Deco system.

As to the IP addressing and my reference to this above, you have to ensure the T-Mobile gateway is not assigning IP addresses on the same subnet/block of IP addresses the Deco is configured to hand out to devices connected to the Deco......this is for the situation the Deco is running in router mode. If the Deco is running in AP mode, then none of this applies.

 

Got it. Thanks a lot. Now, the picture is getting clearer. I appreciate your time.

Regarding the word 'gateway' I meant the original t-Mobile combo. To me, deco is just a router.

 

Update: I received my 3 pack mesh. installed the phone app for setup. Followed the instructions. The app knew the connection type "Dynamic IP' right away. When I set up the remaning 2 nodes, I stayed in the same room where T-Mobile gateway is. (Some Amazon reviewer recommended that.). It was easy. Placed one on the first floor and the last in the basement.
I used Ookla's speed test on iphone and chromebook in different parts of the house. My speed (with Deco) increased tremendously. I dediced to use the first node (attached to T-Mo's gateway) as a router.
Happy camper here.