User's Manual

System Configuration
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5
ALG Configuration
This page is used to enable or disable customized Application Layer Gateway (ALG)
traversal filters for SIP, H323, IRC, PPTP, SNMP, and TFTP applications.
Click FIREWALL, ALG Configuration. Enable ALG traversal filters for the required
applications, and click Apply.
Figure 5-45 ALG Configuration
Field Attributes
• ALG Configuration – Allows Application Layer Gateway (ALG) traversal filters to
be used to support address and port translation for specified application layer
control/data protocols.
• Services – Services for which customized NAT traversal filters are supported.
- SIP – Session Initiation Protocol is used for Internet conferencing, telephony,
events notification and instant messaging.
- H.323 – ITU-T standard that defines protocols used to provide audio-visual
communication sessions on any packet-based network. It is widely deployed by
service providers to support both voice and video services over IP networks.
- IRC – Internet Relay Chat
- PPTP – Point-to-Point Tunneling Protocol is a method for implementing virtual
private networks.
- SNMP – Simple Network Management Protocol.
- TFTP – Trivial File Transfer Protocol.