D-Link DSR-1000AC User Manual - Page 180

Section 8 - Security Path: Security > Firewall > ALGs ALGs Application Level Gateways (ALGs) are security components that enhance the firewall and NAT support of this router to seamlessly support application layer protocols. In some cases enabling the ALG will allow the firewall to use dynamic ephemeral TCP/ UDP ports to communicate with the known ports a particular client application (such as H.323 or RTSP) requires, without which the admin would have to open large number of ports to accomplish the same support. Because the ALG understands the protocol used by the specific application that it supports, it is a very secure and efficient way of introducing support for client applications through the router's firewall. 1. Click Security > Firewall > ALGs tab. 2. Toggle the protocol(s) to ON that you want to allow through the router. D-Link DSR-Series User Manual 167