Remote control of a mobile router?

Question

network hardware

Why do 99% of mobile routers, be it alcatel or MTS835FT, do not have the ability to remotely connect to them?

I need to send and receive SMS, but I don't really want to mess around with gsm or buy GoIP or its analogues.
The first is long and I'm a so-so electrician, the second is expensive.

And I would just like the ability to remotely send and receive SMS from these routers. Their web interfaces have such an opportunity, but you can enter this web interface only from the local area. Are there any firmware or any specific models of routers with the ability to remotely connect to their web.
PS There was an assumption that if you open port 80 and specify 192.168.0.1 in the local ip, then I can access the panel using the external ip, but this is not so. I ask for help at least in which direction to dig.

Answer 1

Yes, it’s not a matter of denying access, but the fact that in 99% your SIM card in the router will receive a gray (not globally routable) IP and will be behind the provider’s NAT: you won’t be able to connect from outside

Answer 2

Because niche requirements and standards do not provide for this.
1. As already mentioned above, most opsos use nat subnets for mobile clients, which is why simple access to hosts is technically difficult.
2. According to the standards, there is no need for providers to remotely manage these gateways, as they do with xPON and xDSL terminals, the settings are loaded using other protocols.
3. As part of information security, networks and clients are isolated from extraneous traffic that is not safe by default.
4. The mobile modem is always a gateway between the opsos public network and the client's private network, in such a scheme there are no cases with the need for remote control via wan, like wired routers that can separate subnets in networks.

Answer 3

And there is nowhere to dig. According to security requirements, external access is disabled at the firmware level and it is not possible to enable it in principle, firstly, and secondly, all these mobile whistles and routers are behind nat, and even if access is open on port 80, it still cannot be obtained from the outside. Therefore, only non-standard solutions like crutches with vpn access for themselves, if somewhere there is a white ip and you can place a vpn server there. It is impossible to do anything by regular means.