Using SS7 with Blueworx Voice Response

Blueworx Voice Response for AIX is a high performance interactive voice response (IVR) system which is capable of handling a wide range of voice response applications including voice messaging.

To interact with telephone callers, Blueworx Voice Response needs to be connected to the telephone network or a switch (telephone exchange). For SS7 Support for Blueworx Voice Response this connection must be digital and can be either E1 (30 channels multiplexed at 2.048 Mb per second) or T1 (24 channels multiplexed at 1.536 Mb per second).

Two types of information must flow between the network or switch and Blueworx Voice Response: PCM (Pulse Code Modulated) voice data, and signaling.

There are many options for signaling but the range of signaling types breaks down into two categories: Channel Associated Signaling (CAS) or Common Channel Signaling (CCS). There are two types of Common Channel Signaling protocols in general use: ISDN and SS7. We discuss only SS7 in this information.

The basic principle of CCS is that a data channel (usually 64 kb/s) is allocated to one of the timeslots on a trunk. This data channel is used to send messages between Blueworx Voice Response and the switch or network to control the flow of calls. Such messages for all channels are sent down the same signaling channel, hence the name, common channel signaling.

Blueworx Voice Response can receive incoming telephone calls and make outgoing telephone calls. As such, the only required signaling is to handle the setup and tear-down of telephone calls. This is provided for attachment outside telephone networks (customer premises equipment (CPE) environments) by the built-in CAS and CCS-ISDN signaling protocol handlers of Blueworx Voice Response.

SS7 Support for Blueworx Voice Response provides the equivalent capability for Blueworx Voice Response applications in a network. SS7 Support for Blueworx Voice Response is implemented as follows:

Although the above describes a logical view of the structure of Blueworx Voice Response’s SS7 support, the actual implementation is more complicated in that the SS7 stack and signaling processes can run on different pSeries computers connected by a fast TCP/IP LAN. This allows for a distributed system where a single SS7 controller machine running the SS7 adapter and stack (called the SS7 Server in this information) can control up to six voice processor machines each running Blueworx Voice Response and the SS7 signaling process (called the SS7 Client in this information).

The SS7 Server can be duplicated in a load-sharing configuration to provide high reliability.