How to connect GSM modem to Asterisk?

Colleagues, good day!

The situation is this: there is a physical server with installed Asterisk. To this server via USB connected to a GSM modem (Huawei E173), which uses Asterisk via the module chan-dongle. This configuration is fully debugged and working.

There was a need to connect to Asterisk as a gateway 1-n the same modem. The problem is that this modem should be located in a different region.
To start, prepare the modem took a router with OpenWrt and a USB port, configured the VPN tunnel with the Asterisk server.

Question: how most competently and reliably to implement the idea:
1. Set on router 1-n Asterisk module chan-dongle, which is then used by the primary server as a SIP trunk;
2. To traverse the USB device over the network to the server using, for example, USB over IP tunnel;
3. The other?

I would be very grateful to hear Your opinions and suggestions for implementation.
June 10th 19 at 16:33
2 answers
June 10th 19 at 16:35
I think both have a right to life — but I would choose the first option (except that with IAX instead of SIP). Just because it's easier and more common.

I suspect that the USB over IP not on the local network will not be very responsive — and not sure how to react to this chan_dongle. However, I see difficulties to try both.

About other options — I don't think they exist (and I'm not sure they need).
June 10th 19 at 16:37
Not looking in the direction of the voice gateways that support 3G whistle? (for example TAU-8.IP | 8 port FXS VoIP gateway)
Really don't know how they're doing with the VPN.

Find more questions by tags OpenWrtAsterisk