Forum Discussion
Can you clarify the flow of messages from a Direct Line Speech client to the bot service?
Hi nsouth1625,
Here is a link to the Direct Line Speech docs with a diagram that shows the flow.
Direct Line Speech - Speech service - Azure Cognitive Services | Microsoft Docs
You are correct in that audio is sent to our Azure Speech Service and then from there via the DL Speech channel to your Bot. The Bot is hosted in your app service. On the way back it is sent back via the channel and text that should be rendered as audio is sent to our Speech To Text service.Our services comply with the various security and privacy certifications. Have a look here:
Cognitive Services Compliance and Privacy | Microsoft AzureAs well as: Speech service encryption of data at rest - Azure Cognitive Services | Microsoft Docs
HeikoRa, thank you for the reply and for the info. I have a couple of clarifying questions which are not clear from the diagram:
- When the Speech Service sends info "via the DL speech channel" to my bot, does the DL speech channel imply an intermediary endpoint, the Bot Framework Service? My understanding was that the Bot Framework Service is a somewhat-behind-the-scenes service responsible for sending information between the channel and the bot app. Is my understanding correct?
- You said, "On the way back it is sent back via the channel and text that should be rendered as audio is sent to our Speech To Text service." To clarify, if text does not need to be rendered as audio, does it flow straight back to the client without going to Speech Services?
Microsoft1. Yes the DL Speech channel facilitates the communication between the app using the Speech SDK to send/receive audio and bot messages and your bot. It handles any conversion of audio to text and the other way around where needed. It basically just routes the data to the appropriate place (speech service or bot).
2. If there is no text to render as audio we won't call the text to speech service.