# Basic ALG Configuration

All Application Layer Gateway (ALG) protocols are enabled by default on the security device. When you disable an ALG, all packets using that protocol are dropped.

To enable or disable an ALG, check or uncheck the corresponding check box and click Apply. To configure parameters for the MGCP, H.323, SIP, or SCCP ALGs, select the protocol from the list at the top of the page.

Warning: Note that this feature is CPU intensive and under certain high traffic volume conditions can cause high CPU utilization.