\begin{tikzpicture}[thick, node distance=1em]
	
	\begin{scope}[every node/.style={draw,rectangle,thick},inner sep=1.0em]
		\tikzstyle{level 1}=[sibling distance=6cm,every child/.style  ={line width=4pt},inner sep=0.8em]
		\tikzstyle{level 2}=[sibling distance=3cm,every child/.style  ={line width=2pt},inner sep=0.5em]
		\tikzstyle{level 3}=[sibling distance=1.5cm,every child/.style={line width=1pt},inner sep=0.1em]
		
		\node {Switch}
			child {node {Switch}
				child {node {Switch}
					child {node [circle] {Node}}
					child {node [circle] {Node}}
				}
				child {node {Switch}
					child {node [circle] {Node}}
					child {node [circle] {Node}}
				}
			}
			child {node {Switch}
				child {node {Switch}
					child {node [circle] {Node}}
					child {node [circle] {Node}}
				}
				child {node {Switch}
					child {node [circle] {Node}}
					child {node [circle] {Node}}
				}
			}
		;
	\end{scope}
	
\end{tikzpicture}
