What is the best way to separate system from another in mikrotik router

Hello for all My friends there..
My question like this.
I have a pbx system installed im my office and i want to isolate this system from the other system using mikrotik router, so what is the best from this two method.
1-to separate ports from each another by creating rule..? In my case the pbx system is connected to Eth2 and have 192.168.10.1 ip address. So i droped the forward packet from this address to another address and visa versa and it work well.

2-or to make a Vlans on the same Port so every system has it own Vlan..?
Sorry if my question sound silly im a new in mikrotik.
Thanks in advance.

Your vlan separation would be based on what ?

I prefer physical separation here.

Hello Mr holvoetn..! Thanks for your response..!
Well i didnt understand what you mean by this sentence 'your Vlan separation based on what"
Please Can you clarify more..?

What differentiator, what attribute will you use to separate that PBX system from the rest if they are connected to the same ethernet network ?
Based on that attribute you may (or may not) be able to setup VLANs.
Will be difficult …

The only sensible way I see (and the most secure) is 2 physical ethernet ports. Then you are 100% sure they are separated.

I’d say it’s you who has to clarify more. @holvoetn is right that the safest separation is a physical one; you haven’t stated what is your reason not to separate the two devices physically. Do both need to access internet? Do both need to be managed from the same workstation? I.e. to get a useful advice, provide a useful input - describe, or even better, draw, the desired overall logical topology of the network.

State the use cases never mind the config along with the network diagram to assess your equipment constraints/setup

What single or groups of users do you have (users=people/pcs or devices/printers etc)
What can each single or group entity do, what should they not be able to do…

Then and only then can a rational config be formulated.