As George mentioned, an ACD queue is required for a call to "wait" for an available agent. The other "out-of-the-box" basic queue types (sequential, group, round-robin) will check each agent per the rules of the queue type and then if no agents are available, the call will be delivered to the workgroup's mailbox (if configured) or to the default Attendant Profile.
It is actually possible to customize this behavior in some cases using Interaction Attendant.
Example:
- Create an Attendant profile that handles calls for a certain DNIS value
- Open the Call Processing Style dialog box and choose direct-to-queue processing
- Select the Workgroup radio button and choose the appropriate workgroup queue from the drop down, enter a timeout value, and check the box to perform direct-to-queue processing only once (VERY rarely would you want to leave this unchecked)
- Use the default schedule or other custom schedules under the profile to define actions to be taken at the timeout for the direct-to-queue processing (might be to play a message and then send to voicemail, play a menu with multiple options, or transfer the call to another profile for additional processing)