4g Megafon - tp-link MR3420 - SIP-Phone Link not working!?

Question

SIP

All the best!
I’ll immediately warn the IT specialist, I’m not ah, and therefore I ask you not to kick!
I work in a state structure, there is no full-time programmer!
the task is to organize sip telephony through a 4g modem, the equipment has been purchased and it cannot be replaced!
the problem is in port forwarding, it doesn’t work either, I tried both on standard firmware and on OpenWRT, I do everything through the web interface, since in Linux technologies ZERO!
in fact, the link is working. bringing a router from home asus rt-14, plugged in a modem, plugged in a phone and everything worked without forwarding and so on.
if anyone can write a rule for these settings:
For SIP telephony, incoming UDP ports 5060-5070 signaling,
17000-30000 voice should be opened.
Also, if your equipment is behind NAT, please mirror ports
5060-5070 and 17000-30000.
For the correct operation of the incoming connection, you need to allow the reception of connections from
213.145.43.43, 213.145.43.44, 213.145.43.45, 213.145.43.128, 213.145.43.130,
213.145.43.133,
217.14.248.3 I will be eternally grateful!

Answer 1

Well, it's not serious at all! this scheme does not work when working with 3G / 4G modems in this particular router, on the TP-Link website this matter was discussed admins beat their chests with their fists that everything should be normal, it doesn’t work for users!
It works through WAN but doesn’t work through USB, apparently there is some kind of bug in transferring traffic from a 3G / 4G modem to LAN,
I will repeat if someone starts talking about gray / white ip. The same modem and the same phone are excellent friends through the asuska without forwarding!