This test is to verify the client is reconnecting the server with correct
backoffs as specified in
-[the spec](http://github.com/grpc/grpc/blob/master/doc/connection-backoff.md).
+[the spec](https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md).
The test server has a port (control_port) running a rpc service for controlling
the server and another port (retry_port) to close any incoming tcp connections.
The test has the following flow: