Nuance Speech Server provides an MRCP V1.0 interface to text-to-speech and speech recognition components.
To configure Blueworx Voice Response to connect to a Nuance Speech Server, the default RTSP port number used must match that used for the Nuance Server configuration. By default this value is 4900. An example of the VRBE TTSService entry configuration settings required for text-to-speech in configuration file /var/dirTalk/DTBE/native/aix/default.cff are shown below:
TTSService=Tts_GB PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPTTS InitSessionString=URI=rtsp://1.23.45.678:4900/media/speechsynthesizer TTSType=Ttsen_GB ;
To use dynamic engine allocation for text-to-speech, append ,keepsessionforcall=no to the end of the InitSessionString URI value, as shown in the following example:
TTSService=Tts_GB PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPTTS InitSessionString=URI=rtsp://1.23.45.678:4900/media/speechsynthesizer,keepsessionforcall=no TTSType=Ttsen_GB ;
For larger deployments handling more than one trunk of calls, it may be necessary to use more than one speech server to process text-to-speech and speech recognition requests. To do this a load-balancing application such as WebSphere Edge Server is used to distribute text-to-speech and speech recognition requests to two or more speech servers. All text-to-speech and speech recognition initialization requests are sent to a load-balancing address. The load balancer receives these requests and forwards them to one of a cluster of speech servers. To use Nuance speech servers in this way, a number of changes to Blueworx Voice Response and Nuance configuration need to be made.
TTSService=Tts_GB PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPTTS InitSessionString=URI=rtsp://1.23.45.678:554/media/speechsynthesizer TTSType=Ttsen_GB ;
With load-balanced systems, port 554 is used instead of 4900. The changes required to the Nuance configuration file NSSserver.cfg are:
| Variable | Value |
|---|---|
| server.transport.bindrtptoip | The IP address of the speech server |
| server.rtp.strictSdpMediaPortUse | 0 |
| server.mrcp1.transport.port | 554 |
Text-to-speech requests are forwarded to one of a number of Nuance voice servers using the same port number (554). When a text-to-speech session has been set up on a Nuance voice server and Blueworx Voice Response has received a response, text-to-speech traffic passes to and fro directly (not through the load balancer machine).
Nuance Speech Server provides an MRCP V2.0 interface to text-to-speech and speech recognition components.
An example of the VRBE TTSService entry configuration settings required for text-to-speech in configuration file /var/dirTalk/DTBE/native/aix/default.cff are shown below:
TTSService=TTSMRCPv2 Enabled=yes TTSType=TTS_MRCPv2_type PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPv2TTS InitSessionString=URI=sip:mrcpv2@mrcpv2server.com ;
Lumenvox provides an MRCP V1.0 interface to text-to-speech and speech recognition components.
To configure Blueworx Voice Response to connect to a Lumenvox, the default RTSP port number used must match that used for the Lumenvoxr configuration. By default this value is 554. An example of the VRBE TTSService entry configuration settings required for text-to-speech in configuration file /var/dirTalk/DTBE/native/aix/default.cff are shown below:
TTSService=Tts_GB PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPTTS IInitSessionString=URI=rtsp://test1.blueworx.com:554/media/synthesizer TTSType=Ttsen_GB ;
Lumenvox provides an MRCP V2.0 interface to text-to-speech and speech recognition components.
An example of the VRBE TTSService entry configuration settings required for text-to-speech in configuration file /var/dirTalk/DTBE/native/aix/default.cff are shown below:
TTSService=TTSMRCPv2 Enabled=yes TTSType=TTS_MRCPv2_type PlugInClass=com.ibm.telephony.directtalk.mrcp.MRCPv2TTS InitSessionString=URI=sip:mrcpv2@mrcpv2server.com ;