.PS 7.5i
.ps 20
## figure 24
B1:	box "SESSION SERVICES" width 3*boxwid
B2:	box "PRESENTATION SERVICES" width 3*boxwid with .sw at B1.nw
B3:	box "ASN.1" with .se at (B1.ne.x+boxwid, B1.ne.y+boxht/2) \
		height 2*boxht
B4:	box "\xx DIRECTORY" "" "\xx SERVICES" \
		with .se at B2.ne width boxwid*3/4
B6:	box "\xx ASSOCIATION" "" "\xx CONTROL" \
		with .ne at B4.nw width boxwid*3/4
B7:	box "CCR" with .ne at B6.nw width boxwid*3/4
##
	line from B2.nw \
	     to (B2.nw.x, B3.n.y+boxht/2) \
	     to (B3.nw.x, B3.n.y+boxht/2) \
	     to B3.nw
B5:	box invis width 3*boxwid height B3.n.y+boxht/2-B2.nw.y \
	    with .sw at B2.nw
	move to (B5.n.x, B5.n.y-lineht/2); "FTAM"
##
.PE