sessiond takes the port number as a parameter.  The default port is 54321.

The timeout is currently hardcoded to 200ms.  It seems to be a reasonable value
to allow uninterrupted operation in case of sessiond server failure or a lost
packet.

There is no encryption of sessiond traffic, as the network infrastructure
within a cluster is usually trusted.

Security requirements for the infrastructure:
 - sessiond port must not be accessible from untrusted networks
 - network traffic between stunnel and sessiond must only be accessible by
   trusted personnel
