User manual

VOPTech GoIP User Manual
Voptel Technology Co., Ltd All Rights Reserved. 45
3.5.6 Firewall Penetration
In the advance option of the call setting, the signaling and media have separate firewall setting,
as shown in the following figures.
3.5.6.1 Traversal of H323 Signaling over NAT
The traversal of H323 signaling over NAT (firewall) is classified into 4 categories:
A. No
The mechanism of firewall traversal is not supported.
B. Nat Citron
The Citron is a special firewall traversal protocol for GnuGK and used with GnuGK.
C. Port Transparency/DMZ
The port transparency is used to transfer the network port on the LAN interface to the
computer or the server in the LAN. This feature enables external users (through the Internet in
most cases) to share the services of internal servers (such as FTP, HTTP, and Telnet).
The port transparency supports the address of the gateway and response server. The gateway
is a communication device that connects two different networks. The response server is a
standard service device that implements the ECHO protocol.
D. Trunk Agent
The trunk agent protocol is a firewall traversal technology developed by VOPTEL Technology.
It enables the products of VOPTEL Technology to be applicable for most LANs. It involves
the address of the trunk proxy server, port, user name and password.