Hello,
I work for a security company installing CCTV and Audio. I'm having issues with SIP registration from the speaker to our PBX server. From what I gathered from the speaker manufacturer a Pcap determined the firewall is blocking the data. Unfortunately I'm not an network expert and the customer does not have a clue on how to whitelist an ip. I am familiar with port forwarding, is this a similar process?
Kinda similar, in the sense that for a "port-forwarding" you can also APPLY a white-list. (basically "who is allowed to hit your port-forward")
The only action to take
1) Create a "access-list" and add all the IP's that will be allowed to communicate
2) Apply this list to the specific firewall-rule responsible for the communications (does not have to be a DNAT-rule, depends on the configuration of the Mikrotik)
But your question is rather generic, without more details or a simple schematic it will be difficult to provide more tips.