{{box(0,0)(8,8);inlabel(.4,"Physical")}}
{{box(0,8)(8,16);inlabel(.4,"Data Link")}}
{{box(0,16)(8,24);inlabel(.4,"Network")}}
{{box(9,0)(17,8)}}
{{box(9,8)(17,16);inlabel(.4,"Lap-B")}}
{{box(9,16)(17,20);inlabel(.4,"X25(1980)")}}
{{box(9,20)(17,24);inlabel(.4,"Yellow Book")}}
{{box(18,0)(26,8)}}
{{box(18,8)(26,16);inlabel(.4,"X25(1984)-L2")}}
{{box(18,16)(26,24);inlabel(.4,"x25(1984)-L3")}}
{{label(2,25,.4,0,"Transition to ISO Network Layer")}}