SIP Trunking the route to the new VoIP services

This work gives an overview of SIP-Trunking solution and explains the existing difficulties in implementing VoIP services, when this architecture is deployed in multivendor environment. The causes of these problems are explained with two existing approaches used by carrier to solve interoperability: they are Full Jacket SIP-Trunk and Customized SIP-Trunk. A solution to cover the lackings of SIP standards is the introduction of a SIP adaptation device called “Inter-Domain Adaptation Device” which will increase the potentiality of SIP-Trunking based solutions. It is also proposed a method for assessing the complexity of different approaches to SIP-Trunking applications.