ZyXEL ISG50-PSTN User Guide - Page 338

Chapter 20 ALG 20.2 The ALG Screen Click Configuration > Network > ALG to open the ALG screen. Use this screen to turn ALGs off or on and configure the port numbers to which they apply. Figure 224 Configuration > Network > ALG The following table describes the labels in this screen. Table 106 Configuration > Network > ALG LABEL Enable H.323 ALG Enable H.323 Transformations DESCRIPTION Turn on the H.323 ALG to detect H.323 traffic (used for audio communications) and help build H.323 sessions through the ISG50's NAT. Select this to have the ISG50 modify IP addresses and port numbers embedded in the H.323 data payload. H.323 Signaling Port Additional H.323 Signaling Port for Transformations Enable FTP ALG Enable FTP Transformations You do not need to use this if you have a H.323 device or server that will modify IP addresses and port numbers embedded in the H.323 data payload. If you are using a custom TCP port number (not 1720) for H.323 traffic, enter it here. If you are also using H.323 on an additional TCP port number, enter it here. Turn on the FTP ALG to detect FTP (File Transfer Program) traffic and help build FTP sessions through the ISG50's NAT. Select this option to have the ISG50 modify IP addresses and port numbers embedded in the FTP data payload to match the ISG50's NAT environment. FTP Signaling Port Clear this option if you have an FTP device or server that will modify IP addresses and port numbers embedded in the FTP data payload to match the ISG50's NAT environment. If you are using a custom TCP port number (not 21) for FTP traffic, enter it here. 338 ISG50 User's Guide