.PS
.ps 20
## figure 10
boxwid = 4 * boxwid
B1:	box height 7*boxht/2
B2:	box with .n at B1.s "RTS" height 3*boxht/2
B3:	box with .n at B2.s "SESSION" height 3*boxht/2
B4:	box with .n at B3.s "TRANSPORT SWITCH" height 3*boxht/2
	line dotted from B1.n to B1.s
##
boxwid = boxwid / 4
B1a:	box with .w at (B1.w.x+boxwid/2, B1.w.y) "P1" dashed
B1b:	box with .ne at (B1.ne.x-boxwid/2, B1.n.y-boxht/2) "P3" dashed
B1c:	box with .se at (B1.ne.x-boxwid/2, B1.s.y+boxht/2) "ROS"
	line from B1b.s to B1c.n
##
.PE