# Bandwidth Management - About Call Admission Control

Call Admission Control of Bandwidth Management is a function that admits or rejects incoming calls between zones based on availability of bandwidth.

If a call cannot reach the destination because it encounters a managed point between ICPs in the network that have reached maximum bandwidth, the call follows network congestion handling, allowing alternate routing, for example, over TDM.

If a call reaches the destination ICP, but cannot get to the IP Phone because there isn't enough bandwidth, the call is handled as if the user is busy, for example, the call may go to voice mail.

Related Topics

- Introduction

- About Zones and ZAPs

- Configuration Data is Shared via SDS

- What Features are Supported?