39 • SIP gateway configuration SmartWare Software Configuration Guide466 IntroductionIntroductionThis chapter provides an overview of the SIP gateway and describes the tasks involved in its configuration.When communication is required between different networks a gateway is always needed between them. Agateway provides:• Data format translation, e.g. audio and video CODEC translation• Control signaling translation, e.g. call setup and termination functionality on both sides of a network.In the case of SmartWare, a gateway connects two contexts of different types, For example, the CS and the IPcontext. It handles connections between different technologies or protocols and contains general gateway con-figuration parameters. In SmartWare one of these gateways is the SIP gateway. This is an implementation of aSession Initiation Protocol (SIP) User Agent according to RFC 3261. The SIP gateway uses SIP CS interfaces,which are explained in detail in the chapter about SIP Interface Configuration. The SIP interfaces in the CScontext must be explicitly bound to a SIP gateway. The SIP gateway itself must be bound explicitly to an IPinterface in the IP context. Figure 78 illustrates the function of the SIP gateway. SmartWare supports multipleinstances of the SIP gateway.Figure 78. SIP Gateway between IP and CS contextsGateway configuration task listThis chapter describes the configuration of the SIP gateway. Some parameters can be configured in the gatewayconfiguration mode and may be overwritten in another configuration mode, For example, in the SIP CS inter-face. For example, the default VoIP profile to be used with the gateway is configured in the gateway configura-tion mode. However it can be overwritten by another VoIP profile specified in the SIP CS interface. Allpossible configurations, which are involved in a specific configuration topic are described in the respective con-figuration task.• Configure DNS resolver• Configure datapath related settings• Binding the gateway to an IP interface