User's Guide

Click the Apply button to save your changes or click the Cancel button to discard
your changes.
ALG
Application Layer Gateway (ALG) consists of a security component that augments
NAT or a firewall. Your Modem Router allows NATs to support address and port
translation for certain application layer protocols such as FTP, SNMP, and others.
To access the ALG page, click Advanced > NAT > ALG or click the ALG Setting button.
FTP — File Transfer Protocol (FTP) is used to transfer files between computers on a
TCP/IP based network, such as the Internet. Check this box to enable this function
to work through your Modem Router.
SNMP — Simple Network Management Protocol (SNMP) is a network protocol used
to monitor the devices connected to a network. Check this box to enable this
function to work through your Modem Router.
RTSP — Real Time Streaming Protocol (RTSP) is a network protocol used for
entertainment and communication systems to control streaming media sessions.
Check this box to enable this function to work through your Modem Router.
SIP — Session Initiation Protocol (SIP) is a signaling protocol used to control
multimedia communication sessions such as voice and video calls over Internet
Protocol (IP). Check this box to enable this function to work through your Modem
Router.
IRC — Internet Relay Chat (IRC) is a real-time Internet chatting protocol designed for
group communications. Check this box to enable this function to work through your
Modem Router.
H323 — H.323 is a standard that provides audio-visual communication sessions on a
network. It is widely implemented in voice and video conferencing equipments and
is used within various Internet real-time applications such as NetMeeting. Check this
box to enable this function to work through your Modem Router.
It is recommended to retain the default ports of these protocols.