digraph ntp{
label= "vereinfachte NTP Hierarchie";
ranksep=.75;

//skala
{
node [shape=plaintext]
0 -> 1 -> 2 -> 3 -> 4 ;

}

// 
{rank = same; "0"; 
ptb [label="Atomuhr der PTB",shape=circle];}


{rank = same; "1"; 
s11 [label="Stratum 1\n131.188.3.221",shape=box];}


{rank = same; "2"; 
s21 [label="Stratum 2 Server\n141.82.30.253",shape=box];
s22 [label="Stratum 2 Server\n141.82.30.252",shape=box];
}

{rank = same; "3";
s31 [label="Stratum 3\n192.168.1.11",shape=box];
s32 [label="Stratum 3\n192.168.2.11",shape=box];
s33 [label="Stratum 3\n192.168.3.11",shape=box];
}


{rank = same; "4"; 
ws1 [label="Workstation 1\nNetBSD/Alpha",shape=box];}


// 0 - 1
ptb -> s11 [label="DCF77 PZF"];

// 2 - 2 
s21 -> s22 [label="Sync über Buddy"];
s22 -> s21 ; 

// 2 - 1
s21 -> s11 [label="Zeitanfrage als Slave"];
s11 -> s21 [label="Zeitantwort als Master"];

// 3 - 2
s31 -> s21 [dir=both,label="Zeit"];
s31 -> s22 [dir=both]; 
s32 -> s22 [dir=both]; 
s33 -> s21 [dir=both]; 

// 3 - 4
ws1 -> s31 [dir=both,label="Zeitsynchronisation"];
ws1 -> s32 [dir=both];
ws1 -> s33 [dir=both];

}