3.2.2.4.1.4 Create a Call
A new call MUST be created by using the current activity ID and sequence number. The new call MUST have Call State set to STATE_QUEUED, F_CANCELED MUST be set to false, CANCEL_EVENT_ID MUST be set to zero, the Sent Fragment List and Received Fragment List MUST be cleared, and the Receive Fragment Base MUST be set to zero.
The new call is added to the activity's List of Active Calls.
If the Activity's Current Call is NULL, the Activity's Current Call is set to the call just created. The Call State (for this new call) is set to STATE_SEND_FRAGMENTS, and the client MUST send one or more request fragments.