Its my understanding that you would be given some data, baed on the OID you could tell what its related to.  I dont understand how it would be configurable.

Also, I think clarification is in order here.  There are two basic methods for doing SNMP, traps where FreeSWITCH would send to some SNMP monitoring agent and gets, where a client would poll FreeSWITCH for information.  It is my understanding that traps are not currently supported, although my futher understanding is that its desired they would be.

To get alarms in realtime you would likely want traps to be sent, so that you can see them as they happen.  Polling via a SNMP get would work but you dont always want to poll too frequently as it does cause some load however minor.

As for logging, it would be on the SNMP module to decide what gets logged.  There is an eventing system already within  the core of FreeSWITCH that would enable a SNMP module to monitor certain things.  This would be similar to how the CDR modules work, except on other events.  It would be upto the other modules to push events they think are desirable, such as a red alarm on a pri line in mod_wanpipe.  The SNMP module would (presumably by configuration file) see that event, decide its worthy to be sent out, and send it. 

It should not be configured for each module to say what to do with it, it should instead be on the event omnitor modules such as SNMP to decide if they want it.  So, you could have a module that wants critical events, and would send an email, as well as an SNMP module that would fire a trap, and whatever else, and they can all see the events as they happen.  This already exists, its a matter of getting the modules to react to the events that is missing.