• A congestion alarm is raised.
• Calls that exceed the CAC maximum values are not allowed.
• Calls from extensions to public trunks through Alternate Route Selection (ARS) are queued and display Waiting for Line.
• Calls from extensions to public trunks which do not route through ARS receive a fast-busy tone and display Congestion.
• Idle phones display Emergency/Local calls only.
• Alternative routing to a local PSTN gateway follows ARS priority escalation rules.
• SIP calls that would exceed call limits and have no other targets are declined with cause=486 or cause = 503.

Allowed calls

• Emergency calls are always allowed.
• Established calls are never torn down to achieve limits.
• A phone on a remote site that parks a call is always allowed to retrieve it.
• Request Coaching Intrusion calls are allowed.