Are there devices that are both a GSM VoIP gateway and a 4G modem?

Question

SIP

I imagine it like this:
Option 1. A box that looks like a router with a large GSM antenna. A SIM card is inserted inside. An ethernet cable comes out of the box, which connects to the WAN of the main router (we get 4G Internet on the local network). Using the IP address of the device, you can connect an external telephone line to Asterisk (incoming and outgoing calls via the GSM network).
Option 2. The same, but with a USB modem. Here, probably, there are more subtleties and "finishing with handles".
In general, will the mobile network allow you to use the Internet and talk at the same time?

Answer 1

IMHO, if it’s real, then it will be a router with a USB port into which you plug a 4G whistle .... and then dancing with a tambourine =)

Answer 2

In general, will the mobile network allow you to use the Internet and talk at the same time?

No, it won't. Either voice or data transmission. Separate no problem.

Answer 3

I do not know the answer to your question, but I am inclined to the opinion of solalex .
On the second point: take a microtic (for example, MikroTik RB951Ui-2HnD) and insert a modem stitched into HiLink into it (for example, Huawei E3372 (instructions: w3bsit3-dns.com/forum/index.php?showtopic=582284)).
There are enough manuals on the forum, everything is extremely simple. Only on the firmware moment: first we read in full and perform all the installations of the programs (you need to install 3 programs) and there will be happiness.
This scheme itself works in 3 copies, but there is a nuance: at high speed in 4G, it seems that the modem does not have enough USB power and it reboots. I did not try to feed through the amplifier to confirm my assumption.