DIR-620S  Wireless N300 Router with 3G/LTE Support and
USB Port
User Manual
Configuring via Web-based Interface
ALG/Passthrough
On the Advanced / ALG/Passthrough page, you can allow the router to use RTSP, enable the 
SIP ALG and PPPoE/PPTP/L2TP/IPsec pass through functions.
SIP is used for creating, modifying, and terminating communication sessions. This protocol allows 
telephone calls via the Internet.
RTSP   is   used   for   real-time   streaming   multimedia   data   delivery.   This   protocol   allows   some 
applications to receive streaming audio/video from the Internet.
The PPPoE pass through function allows PPPoE clients of computers from your LAN to connect to 
the Internet through connections of the router.
The PPTP pass through, L2TP pass through and IPsec pass through functions allow VPN PPTP, 
L2TP and IPsec traffic to pass through the router so that clients from your LAN can establish 
relevant connections with remote networks.
Figure 158. The Advanced / ALG/Passthrough page.
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