When integrating a helpdesk with babelforce, it is common to tag a case/ticket for a call with "call_abandoned" or "call_missed" if the call was not taken by an agent.
To do this, use a babelforce "Call finished" Event to trigger an "Update ticket" action. The important thing is to create a trigger first with conditions to ensure that the action is only fired when a call finishes without any agent taking the call.
The trigger you need will look like this:
Since this trigger will be evaluated at the end of a call, the second condition will only be true if NO agent has taken the call. The first condition just checks that this is only fired when the inbound call leg is ended, e.g. if you are using an account setup where you fire actions based on different call legs.
Your event then uses the above trigger and in the action "Update ticket" your "Tags" tab will need to look something like this:
There are always alternatives to a process. This describes only one way. For instance, you could also have the call_missed tag on every ticket that is created and remove it the moment the call is bridged to an agent. As always, this is all up to you. Build the processes you want!
If this all was a little too fast for you, go back to this article explaining local and global events in more detail. It also features the example of missed calls but uses a slightly different trigger.