I\'m trying to use the Microsoft.Bot.Connector.DirectLine .NET client to connect to my Direct Line Channel. My client application will have many conversations open at once (lik
I think using the Direct Line streaming extensions would be problematic for your purposes. I'm guessing your custom SMS channel would itself be an app service. Since an app service can (and probably should, in your case) be scaled so that multiple instances are running simultaneously, suppose two SMS messages from the same conversation go to two instances of your channel. In addition to having each instance of your channel using many web sockets to talk to many bots, multiple instances of your channel may use duplicated web sockets to talk to the same bot. There's also the problem of each bot itself needing to support streaming extensions.
Rather than using using Direct Line streaming extensions, you might consider using traditional Direct Line. This would involve receiving activities from the bots by polling a Direct Line endpoint.
Since Direct Line is a channel itself that you'd be using on top of your own channel, you might also consider cutting out Direct Line altogether. That way you wouldn't have two channels between the user and the bot. You could send HTTP requests to each bot's endpoint directly, and the activities the bots would receive would contain the service URL for your channel, allowing your channel to receive messages from the bots.