ZyXEL Communications ZyWALL 110 Series, User Manual, Page: 237 / 562

Chapter 15 ALG
ZyWALL 110/310/1100 Series User’s Guide
237
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
Transformations Select this to have the ZyWALL modify IP addresses and port numbers embedded in
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
Inactivity Timeout Select this option to have the ZyWALL apply SIP media and signaling inactivity time
out limits.
SIP Media Inactivity
Timeout Use this field to set how many seconds (1~86400) the ZyWALL will allow a SIP
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
Timeout Most SIP clients have an “expire” mechanism indicating the lifetime of signaling
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
Transformations Select this to have the ZyWALL modify IP addresses and port numbers embedded in
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
Signaling Port for
Transformations If you are also using H.323 on an additional TCP port number, enter it here.
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
Transformations Select this option to have the ZyWALL modify IP addresses and port numbers
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
Port for
Transformations If you are also using FTP on an additional TCP port number, enter it here.
Apply Click Apply to save your changes back to the ZyWALL.
Reset Click Reset to return the screen to its last-saved settings.