mpp.mrcpsessionrefresh.timer
Use this timer as a guard against a speech server failure while playing prompts or using ASR. You can also use this timer to generate some traffic when speech is not being used to prevent a speech server session timeout.
mpp.mrcpsessionrefresh.timer value should always be set to 20 seconds lesser than the speech server session timeout value. This value must be larger than the largest prompt to be played and must be longer than the longest expected ASR response.
The session timeout value is 60 seconds by default for Nuance. On each Nuance speech server, modify the value in the server.mrcp2.sip.sessionTimeout for MRCP V2 and in server.mrcp1.rtsp.sessionTimeout for MRCP V1 in the configuration file. Other vendors may have a different way to update this value.
For example, if you need to play a prompt that is 180 seconds long, then set the value of mpp.mrcpsessionrefresh.timer to 190 seconds on each MPP server and set the speech server session timeout to 210.