If you are in the informatics sector, it is impossible for you to come to a point where the Mikrotik router does not come.
There are two important points here.
1 – Bridge behind a Mikrotik modem (Username password is defined in Mikrotik)
2 – It is accessible from the outside as a DMZ / NAT behind a Mikrotik modem.
In both methods, a WAN IP belonging to the Mikrotik device (this is the local IP in option 2.) I also assume that there is a LAN IP (Local, camera, office IP, etc).
Users are already on the Internet and you can access your external IP address (WAN IP) information from the external network (mobile phone or other internet connection) and you can access the Mikrotik interface.
In this case, the command line should be done as follows.
/ip firewall nat add chain=dstnat action=dst-nat to-addresses=kkk.aaa.mmm.iipp to-ports=3378 dst-address=www.aaa.nnn.iipp dst-port=3378
dst-address=www.aaa.nnn.iipp In this area, you need to have your IP address that appears on the internet.
dst-port=3378 In this area, you must specify which port (WAN) requests will be received from outside. Usually the same value is used with the internal port.
to-addresses=kkk.aaa.mmm.iipp Your camera, IP address or NVR, IP address is required in this field. Or RDP remote tabletop for server IP address
to-ports=3378 In this field, the appropriate port of the nvr, dvr, rdp device in the internal network should be defined.
After writing the rope information in the relevant fields, the camera, never, dvr, rep or any other port you want to forward will be processed.