.PS
.ps 20
## figure 3
boxwid	=	3*boxwid
define boxit @
	box "$1" with .n at ($2.s.x, $2.s.y-lineht/2)
	line from $2.s to last box.n
@
define peer @
	box "$1" with .n at ($3.s.x, $3.s.y-lineht/2)
	line    from $3.s to last box.n
	line $4 from $2.e to last box.w
@
##
B1:	box "APPLICATION"
B2:	boxit(PRESENTATION,B1)
B3:	boxit(SESSION,B2)
B4:	boxit(TRANSPORT,B3)
B5:	boxit(NETWORK,B4)
B6:	boxit(DATA LINK,B5)
B7:	boxit(PHYSICAL,B6)
##
P1:	box "APPLICATION" with .w at (B1.e.x+4*linewid, B1.e.y)
	line dashed from B1.e to P1.w
P2:	peer(PRESENTATION,B2,P1,dashed)
P3:	peer(SESSION,B3,P2,dashed)
P4:	peer(TRANSPORT,B4,P3,dashed)
P5:	peer(NETWORK,B5,P4,dashed)
P6:	peer(DATA LINK,B6,P5,dashed)
P7:	peer(PHYSICAL,B7,P6,)
##
.PE