How to forward a provider network inside the Mikrotik network?

Question

Mikrotik

Good day.
Several points on the satellite Internet, all the necessary services are connected to organize sip communications at the points. On the old provider, which repurchased services from a real satellite provider, a range of / 29 real IPs was allocated. On the new one (directly, without outbidding), 1 white ip per point is allocated, according to the StaticNAT method (translation of packets that came to the white ip to a specific gray ip). There is a Mikrotik at the point, which counts the traffic. When the white IP was real, everything worked clearly, 4 phones per point, two simultaneous calls - no problem. Now that one more NAT has been added, phones registered second (third, fourth) stutter, even when their call is the only one. Any phone that appears on the network first works fine. The rest are not. If you take out all the phones in the provider's network - they all work fine. I visited the thought how to take the phones to the provider network and leave them behind the Mikrotik at the same time. I'm not familiar with VLANs and can't figure out how to do this specifically, I just assume that it's possible to forward the provider's network for Mikrotik through VLAN to isolate it from the main network.
Unfortunately, it is unrealistic for each individual phone to throw its own line from the provider's equipment for geographical reasons.
I ask for advice, how best to implement this with the help of Mikrotik and, possibly, something else?
That's pretty much how I see it.

Answer 1

Either ports on Mikrotik, which include phones, to the Bridge with the port where Vneshka comes, or really separate them from VLAN, on a controlled switch.
But if there is no controlled hardware, then we separate the phones into a separate stupid switch, and we stick this switch into the port that is in the same bridge with the external channel (or generally into the port for which the external port is specified as MASTER)