How to keep track of established connections using WebSockets

I am trying to get a real-time chat service for cross-platform devices to life. The problem is that
System.Net.WebSockets namespace doesn’t allow me directly to keep track of an established connection. I could take a sessionID of the current connection but how can I say perform the following action await socket.SendAsync(buffer, WebSocketMessageType.Text, CancellationToken.None) for a specific client?