Mikrotik SIP ALG is called a SIP Helper and is located under /IP>Firewall>Service ports. The SIP Helper feature must be disabled to properly allow VentureTel VoIP traffic to pass through the Mikrotik router.
To disable, run this command from the terminal:
/ip firewall service-port disable sip
Or from winbox just navigate to IP>Firewall and then click on the Service Ports tab and disable it through the GUI.
If SIP helper is enabled, you may experience things like dropped calls, delayed audio, delay in answering and phones not ringing.