3.2.2.5.10 FACK
The Outbound Fragment Window MUST be updated, and the client SHOULD send a burst of REQUEST fragments. When a FACK PDU is received, the corresponding fragment MUST be removed from the Sent Fragment List.
If a FACK PDU is received for a fragment number that is higher than the fragment number for any other fragments in the Sent Fragment List then those fragments are retransmitted.
If the server has received all request fragments, the Call State SHOULD change to STATE_DISPATCHED. When the Call State changes to STATE_DISPATCHED, this MAY trigger a call queuing operation as described in section 3.2.2.4.1.5.