In a Blueworx Voice Response Voice over IP system, signaling information is sent and received through the AIX system unit LAN connection (usually Ethernet). This should be connected to an IP network such that all other SIP UAs (such as gateways, and phones) can contact each other over the network.
The DTNA adapter only handles the RTP voice data (not SIP signaling) and could be on a separate, and possibly dedicated, network interface to ensure that the voice real time data transfer is not adversely affected by other traffic.
For greater security, Blueworx Voice Response supports IPSEC over the system Ethernet that carries the SIP signaling (this is a feature of AIX). For more information on IPSEC see SIP and IP support.
To provide SIP signaling support, Blueworx Voice Response uses a SIP signaling stack that allows Blueworx Voice Response to communicate over the system unit IP network adapter and a Blueworx Voice Response signaling process that links the SIP signaling stack to Blueworx Voice Response using the standard signaling library API. These are integrated within a single Blueworx Voice Response signaling process (the VoIP-SIP custom server).
When you configure Blueworx Voice Response for Voice over IP, Blueworx Voice Response installs the VoIP signaling process for the channels you require. Inbound and outbound signaling for those channels then flows through the signaling process and the SIP stack to the IP network (rather than over T1 or E1 trunks as would happen in a system with DTTAs installed).