Relationships Between Tasks, Sessions, Contacts, and Channels
When installing and configuring Unified IP IVR, you must understand the concepts, call flows, and configuration dependencies explained in this section:
Task: The Unified CCX receives the incoming call/contact signal on a Trigger, which is then assigned an Application. The application can be a workflow application, a CM Telephony application, (and in a Unified CCE system) an ICM Translation Routing application or an ICM Post-Routing application. When the Unified CCX accepts the contact, the application starts an application task. The application task in turn invokes an instance of a script associated with the application.
Session: A session tracks Contacts as they move around the system. This enables information to be shared among contacts that are related to the same session.
When a contact is received (inbound) or initiated (outbound), the Unified CCX checks to see if an existing session already exists with that contact's Implementation ID. The Implementation ID is the Unified CM Global CallID plus the Unified CM node (GCID/<node>). If a session already exists for the contact, the Unified CCX associates it with that session. If there is no session for the contact, the Unified CCX automatically creates one.
After the contact ends, the session remains idle in memory for a default period of 30 minutes before being automatically deleted.
Contact. A contact can be a Call, an HTTP request, or an email. A contact carries attributes such as creation time, state, language, and so on.
Channel. Each type of contact can have various channel types associated with it. Channels are allocated and associated with contacts as needed and are used to support performing actions on contacts.
Different types of channels are allocated based on the type of contact and the type of dialogue that needs to be supported between the Unified CCX and the Contact. For example, a CM Telephony call that is presented to Unified CCX will be connected to a CTI Port. To support the call control event transfer, a Call Control channel is allocated.
If the Trigger is associated to a Primary and or Secondary Dialogue Group, depending on the type, a Media Channel or an MRCP channel will be allocated.
If an application is triggered by an HTTP Trigger, an HTTP Control Channel will be allocated.