5. Look at what's happening: The master logs in into the slave, starts pppd, and redirects this all thing into a local pty. It consists of the following steps: allocating a new pty sshing into the slave running pppd on the slave the master runs pppd in this local pty and sets up the routing table on the client. There are (not very tight) timing considerations involved, this is why that 'sleep 10s'.