Chapter 14 ALG
ZyWALL ATP Series User’s Guide
350
Figure 240
Configuration > Network > ALG
The following table describes the labels in this screen.
Table 141 Configuration > Network > ALG
LABEL
DESCRIPTION
Enable SIP ALG
Turn on the SIP ALG to detect SIP traffic and help build SIP sessions through the Zyxel
Device’s NAT. Enabling the SIP ALG also allows you to use the application patrol to
detect SIP traffic and manage the SIP traffic’s bandwidth (see
Enable SIP
Transformations
Select this to have the Zyxel Device 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 Zyxel Device apply SIP media and signaling inactivity time
out limits. These timeouts will take priority over the SIP session time out “Expires” value in
a SIP registration response packet.
SIP Media Inactivity
Timeout
Use this field to set how many seconds (1~86400) the Zyxel Device 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 Zyxel
Device deletes the audio session. You cannot hear anything and you will need to make
a new call to continue your conversation.