A comparative study of direct and indirect static peering for inter-domain sip calls

Voice over IP (VoIP) has a promise future in communication era. VoIP services can be delivered through different means of protocols. Session Initiation Protocol (SIP) is a common protocol used to initiate, modify and terminate voice call between two parties. One SIP service provider can peer with others through what it called SIP peering. The main aim of SIP peering is not only bring all together but also share other services such as free of charge calls. Technically, SIP peering might be achieved through different scenarios such as Static Direct Peering, Static Indirect Peering or On-demand Peering. Each of such constructs from several functions and relationships which however characterize the peering addressing and routing. In this paper we made a comparative study of Direct and Indirect Static Peering and we found that Indirect Peering is more involved in VoIP industry as it known for its simplicity, efficiency, trusted party and high opportunity of having free voice calls.