Call Admission Control (CAC) cannot be applied in all cases, for example, a call placed on hold can always be retrieved. The following list identifies features that will always be allowed to connect.
ACD Calls
Add Held
Attendant Serial Call
Call Park - Original Attendant Hold
Call Waiting Swap
Call Park
Call Pickup
Call Pickup - Clustered
Campon - Call Waiting
DSS/ BLF
Emergency Services
Fax calls (See Note below)
Group Page
Hold Retrieve (Hard Hold, Hold on Hold)
Loudspeaker Paging
Music - Background
Music on Hold
Non-Busy Station
Override
Recall
Record-a-Call
Silent Monitor
Stack Hold
TAFAS
Transfer
Wakeup Calls
NOTE: Fax calls are admitted even if they exceed the programmed bandwidth limits between zone access points. The reason for this is timing. CAC does not know at the time that it decides whether or not to admit the call which audio codec will be used to encode the fax transmission. Thus, a fax call between two switches that starts out using a G.711 codec (which consumes 88 kbytes of bandwidth), will be allowed through even when the bandwidth limit between the switches is 32 kbytes.