Measure the time it takes for DC connection

Sometimes it takes a while to get a data channel connection.

## Slow 🐌 

One client in a docker container with `--network=host` on raspberry pi2 and second client on a different machine outside of docker. Both of these on the same local wifi network.

## Fast ⏩ 

Both clients on host machine OR both clients on two different docker containers on the same rpi2.