Preparing the Telephony Infrastructure

Published: June 20, 2005

Preparing the Telephony Infrastructure

Microsoft Speech Server (MSS) deployments that support telephony (voice-only) applications require appropriate telephone lines and related equipment and services.

Contact a telephone system service representative for assistance in configuring the necessary telephony equipment and associated services.

Telephony Channels

A channel, in the context of telephony, is the smallest subdivision of communication that carries voice information between the calling party and the called party. For MSS, channels are the voice communication links between a switched network (either public or private) and the MSS platform components that enable callers to hear and talk to MSS applications.

Voice channels carry information in either analog or digital form based on the type of equipment being used. Analog equipment carries one voice channel per physical medium or line. Digital equipment can carry multiple voice channels per physical medium. For example, a T1 line, which is the standard for digital transmission in the United States, can simultaneously carry 24 digital voice channels.

Depending on the telephony interface manager (TIM) software that you are using with Telephony Application Services (TAS), the following types of lines can be used to carry voice traffic:

  • T1 - Channel Associated Signaling (also known as robbed-bit)

  • T1 ISDN

  • Analog

See the documentation for the TIM software manufacturer for details on the supported signaling protocol for the different line types.

Telephony Boards

Each computer that runs TAS requires TIM software and possibly a hardware telephony board that accepts line connections. See the documentation for the TIM software manufacturer for information about telephony boards that are supported, for any telephony board software requirements, and for installing and configuring telephony boards. For more information on TIM, see Installing Telephony Interface Manager Software.

Telephone lines can be connected to a telephony board directly from the public-switched telephony network (PSTN) of the telecommunication service provider.

MSS supports the following telephony boards.





















MSS supports one telephony board (analog or digital) per server running TAS. Even though the highest-capacity board can carry 96 telephony channels, many factors influence the capacity of MSS to handle callers, such as application design and hardware topology. For more information about capacity guidelines, see Capacity Guidelines.

PBX System

This section applies to MSS Enterprise Edition only.

When running TAS on multiple computers in a server farm configuration, a Private Branch Exchange (PBX) system is required for routing calls to a specific TAS computer. A minimum of two TAS computers are recommended for availability reasons. If one TAS computer fails or is offline for maintenance, one TAS computer is still available to respond to calls.

See the PBX manufacturer's documentation for more information on installing a PBX system, how to configure a PBX for automatic routing to different TAS computers in the case of computer failure (also known as setting up a hunt group), and best practices for maintaining service availability.