User manual

得伯乐科技有限公司
DBL Technology Limited GoIP User Manual
Web: www.dbltek.com
Tel: [phone]
Note: This feature needs the support of the server developed by DBL 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 DBL Technology. It
enables the products of DBL Technology to be applicable for most LANs. It involves the address, port,
user name and password.
The trunk agent protocol supports encryption on communications over the gateway. This feature
needs the support of the server developed by DBL Technology.