How does the DataMiner software forward alarms to other NMS? Does this require an additional license?
Specific to alarm information, DataMiner Web Services APIs expose methods (SOAP, JSON) to request alarm data.
HTTP POST endpoints:
http(s)://[DMAIP]/API/v1/Json.asmx/GetAlarms
http(s)://[DMAIP]/API/v1/Json.asmx/GetAlarmDetails
On top of that there's also a possibility to connect to a websocket, which will allow you to subscribe to events that also include the alarm information. Once this websocket is opened and the correct alarm data subscription is activated, DataMiner will automatically forward any alarm matching the subscription in real time to its destination over the websocket.
Websocket GET endpoint:
wss://[DMAIP]/API/v1/WebSocket.ashx
Just for sake of completeness, there's also an option in DataMiner to activate a TCP-IP socket where you can get the alarms in plain text format. More information about this is also available in the DataMiner Help (in the section "TCP-IP Sockets").
Dataminer can forward all (or a filtered subset) of alarms to any 3rd party system by using SNMP traps.
Alternatively, the alarms call also be retrieved by a 3rd party system using SNMP polling or the HTTP API queries.
In total 3 options are supported: Web Services (explained here) next to TCP-IP sockets and SNMP Trap Forwarding (see other responses).