D-Link DSR-150 - Algs

D-Link DSR-Series User Manual 191
Section 8 - Security
ALGs
Path: Security > Firewall > ALGs
Application Level Gateways (ALGs) are security components that enhance the rewall and NAT support of this
router to seamlessly support application layer protocols. In some cases enabling the ALG will allow the rewall
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 specic application that it
supports, it is a very secure and ecient way of introducing support for client applications through the router’s
rewall.
1. Click Security > Firewall > ALGs tab.
2. Toggle the protocol(s) to ON that you want to allow through the router.