Huawei DR814Q - Manual (Page 70)

User Manual
Aolynk DR814Q ADSL2+ Broadband Router
5 Advanced Configuration
65
Figure 5-29 Delete a security trigger
In fact, the DR814Q has provided an Application Level Gateway (ALG) for NetMeeting.
NetMeeting applications can be also normal even if the port trigger is not configured.
The following example is taken to show how to configure a port trigger if the DR814Q
does not provide the ALG for NetMeeting.
Suppose your PC is connected to the LAN interface of the DR814Q, and you want to
use NetMeeting to have an audio/video chat with Internet users, and to apply
whiteboard and program sharing.
Analysis:
A NetMeeting call is established on the TCP 1720 port. After the connection is
established, NetMeeting needs to re-enable the TCP 1503 port to use whiteboard and
program sharing. NetMeeting also needs to enable any port of TCP and UDP protocols
within the range of 1024 to 65535 to transmit audio and video signals. After the firewall
is enabled, you can configure the port filtering policies and virtual servers of TCP and
UDP protocols to all ports within the range. In this way, Internet users can actively call a
LAN user during the use of NetMeeting. However, possible omission in configuring the
filtering policy and virtual server may cause the failure of the audio/video chat
establishment. Moreover, the virtual server configuration exposes almost all the LAN
host ports to the Internet, resulting in the insecurity of the host.
To solve these problems, you can perform the configuration as below to make the TCP
1720 port trigger TCP/UDP port within the range of 1024 to 65535.
Figure 5-30 Example of the trigger configuration