VoIP is becoming a low-priced and efficient replacement for PSTN incommunication industries. With a widely growing adoption rate, SIP is anapplication layer signaling protocol, standardized by the IETF, for creating,modifying, and terminating VoIP sessions. Generally speaking, SIP routes a callrequest to its destination by using SIP proxies. With the increasing use ofSIP, traditional configurations pose certain drawbacks, such as ineffectiverouting, un-optimized management of proxy resources (including CPU and memory),and overload conditions. This paper presents OpenSIP to upgrade the SIP networkframework with emerging technologies, such as SDN and NFV. SDN provides formanagement that decouples the data and control planes along with asoftware-based centralized control that results in effective routing andresource management. Moreover, NFV assists SDN by virtualizing various networkdevices and functions. However, current SDN elements limit the inspected fieldsto layer 2-4 headers, whereas SIP routing information resides in the layer-7header. A benefit of OpenSIP is that it enforces policies on SIP networkingthat are agnostic to higher layers with the aid of a Deep Packet Inspection(DPI) engine. Among the benefits of OpenSIP is programmability, cost reduction,unified management, routing, as well as efficient load balancing. The presentstudy implements OpenSIP on a real testbed which includes Open vSwitch and theFloodlight controller. The results show that the proposed architecture has alow overhead and satisfactory performance and, in addition, can take advantageof a flexible scale-out design during application deployment.
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