How to help students talking more in online class

There are some factors of online class reducing students' talking. For example, less connection between the teacher and students, looser relationship between the students, the environment changing from classroom to online class, and the technical limitation of online platform. Realizing these factors, the teachers can play a more active role by creating a safer environment for students talking. Many resources and tools online can also help teachers realize the goal. I would like to share my experience of teaching in University of New Hampshire, USA and discuss it with colleagues from all over the world.