User manual

VOPTech GoIP User Manual

The trunk agent protocol supports encryption on communications over the gateway. The H323

trunk agent protocol supports encryption on signaling in different modes (for details about the

agent mode, see section 3.5.6.3 “Media NAT Traversal”).

Note: This feature needs the support of the server developed by VOPTEL Technology.

3.5.6.2 Traversal of SIP Signaling over NAT

The traversal of SIP signaling over NAT (firewall) is classified into:

A. No

The mechanism of firewall traversal is not supported.

B. STUN (RFC 3489)

The Simple Traversal of UDP over NAT (STUN) is a protocol that enables the SIP phone to

detect the existence and type of the firewall installed in the computer. This parameter indicates

the SIP address of the STUN server.

C. 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, port, user name and password.