.PS
picwid = 5i
boxwid = 1.5i
boxht = 1i
ellipsewid = boxwid/2-0.1i
ellipseht = boxht/2-0.1i

Home: box
Serv: ellipse at Home + (boxwid/4,boxht/4) "server"
File: ellipse invis at Home + (boxwid/4,-boxht/4) "files"
User: ellipse invis at Home + (-boxwid/4,-boxht/4) "user"
line from User.ne to Serv.sw
line from File.n to Serv.s
line from Serv.e to (Home.e,Serv.e)
line from Serv.se to (Home.e,Serv.se)

Away: box at Home + (picwid-boxwid,0)
Prog: ellipse at Away + (-boxwid/4,boxht/4) "program"
Sigs: ellipse at Away - (boxwid/4,boxht/4) "sigsrv"

line from Prog.w to (Away.w,Prog.w)
line from Sigs.w to (Away.w,Sigs.w)

line dashed from (Home.e,Serv.e) to (Away.w,Prog.w)
line dashed from (Home.e,Serv.se) to (Away.w,Sigs.w)

arrow height .05i from Sigs.n to Prog.s " signals" ljust
.PE