ZyXEL Communications 110, 1100, 310 manual 237

Chapter 15 ALG

The following table describes the labels in this screen.

Table 87 Configuration > Network > ALG

LABEL	DESCRIPTION
Enable SIP ALG	Turn on the SIP ALG to detect SIP traffic and help build SIP sessions through the
	ZyWALL’s NAT.
Enable SIP	Select this to have the ZyWALL modify IP addresses and port numbers embedded in
Transformations	the SIP data payload.
	You do not need to use this if you have a SIP device or server that will modify IP
	addresses and port numbers embedded in the SIP data payload.
Enable Configure SIP	Select this option to have the ZyWALL apply SIP media and signaling inactivity time
Inactivity Timeout	out limits.
SIP Media Inactivity	Use this field to set how many seconds (1~86400) the ZyWALL will allow a SIP
Timeout	session to remain idle (without voice traffic) before dropping it.
	If no voice packets go through the SIP ALG before the timeout period expires, the
	ZyWALL deletes the audio session. You cannot hear anything and you will need to
	make a new call to continue your conversation.
SIP Signaling Inactivity	Most SIP clients have an “expire” mechanism indicating the lifetime of signaling
Timeout	sessions. The SIP user agent sends registration packets to the SIP server
	periodically and keeps the session alive in the ZyWALL.
	If the SIP client does not have this mechanism and makes no calls during the
	ZyWALL SIP timeout, the ZyWALL deletes the signaling session after the timeout
	period. Enter the SIP signaling session timeout value (1~86400).
SIP Signaling Port	If you are using a custom UDP port number (not 5060) for SIP traffic, enter it here.
Enable H.323 ALG	Turn on the H.323 ALG to detect H.323 traffic (used for audio communications) and
	help build H.323 sessions through the ZyWALL’s NAT.
Enable H.323	Select this to have the ZyWALL modify IP addresses and port numbers embedded in
Transformations	the H.323 data payload.
	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.
H.323 Signaling Port	If you are using a custom TCP port number (not 1720) for H.323 traffic, enter it
	here.
Additional H.323	If you are also using H.323 on an additional TCP port number, enter it here.
Signaling Port for
Transformations
Enable FTP ALG	Turn on the FTP ALG to detect FTP (File Transfer Program) traffic and help build FTP
	sessions through the ZyWALL’s NAT.
Enable FTP	Select this option to have the ZyWALL modify IP addresses and port numbers
Transformations	embedded in the FTP data payload to match the ZyWALL’s NAT environment.
	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 ZyWALL’s NAT
	environment.
FTP Signaling Port	If you are using a custom TCP port number (not 21) for FTP traffic, enter it here.
Additional FTP Signaling	If you are also using FTP on an additional TCP port number, enter it here.
Port for
Transformations
Apply	Click Apply to save your changes back to the ZyWALL.
Reset	Click Reset to return the screen to its last-saved settings.

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ZyWALL 110/310/1100 Series User’s Guide