The Role of Session Border Controllers in the DMZ of Voice over IP(VoIP) Networks

SBCs usually sit between two service provider networks in a peering environment, or between an access network and a backbone network to provide service to residential and/or enterprise customers. They provide a variety of functions to enable or enhance session-based multi-media services (e.g., Voice over IP). This thesis analyzes the internet structure of SBC and shows single-box and dual-box SBCs in the DMZ and introduces firewalls and network address translation. And then explain how the SBC cooperates with the firewalls to ensure that VoIP signaling and media traverses the DMZ without compromising the security of the trusted network. And finally, describes topology hiding and bad protocol detection of other DMZ processing.