ZyXEL Communications armor z2 NT8700-ROG User Manual page 89

ALG Overview
Application Layer Gateway (ALG) allows the following applications to operate properly through the
NBG6817's NAT.
• SIP - Session Initiation Protocol (SIP) - An application-layer protocol that can be used to create
voice and multimedia sessions over Internet.
• H.323 - A teleconferencing protocol suite that provides audio, data and video conferencing.
• FTP - File Transfer Protocol - an Internet file transfer service.
• SNMP - Simple Network Management Protocol - An application-layer protocol that can be used to
exchange management information between network devices.
• RTSP - Real Time Streaming Protocol - An application-layer protocol that can be used to stop,
pause or play video and audio applications streaming on the Internet.
• IRC - Internet Relay Chat - An application-layer protocol that can control the relay chat
applications and allow clients to have real-time communications with others on the Internet.
The ALG feature is only needed for traffic that goes through the NBG6817's NAT.
To change your NBG6817's ALGs and VPN pass-through settings, click Expert Mode > WAN >
NAT > Passthrough. The screen appears as shown.
Figure 59 Expert Mode > WAN > NAT > Passthrough
The following table describes the labels in this screen.
Table 24 Expert Mode > WAN > NAT > Passthrough
LABEL DESCRIPTION
ALG Setup
FTP Select Enable to allow TCP packets with a specified port destination to pass through.
H.323 Select Enable to allow peer-to-peer H.323 calls.
SIP Select Enable to make sure SIP (VoIP) works correctly with port-forwarding and
address-mapping rules.
SNMP Select Enable to allow a manager station to manage and monitor the NBG6817 through
the network via SNMP.
Chapter 10 WAN
NBG6817 User's Guide
89