If

a

machine

"goes

down"

on

the

Internet,

it

is

not

absent:

it

ceases

to

be

part

of

the

virtual

world.

The

code

cannot

call

forth

presence

from

absence:

any

attempts

to

"reach"

that

site

return

nothing,

not

even

the

equivalent

of

the

telephone's

absent

ringing

(or

its

tantalizing

busy

signal).

An

off-line

machine

no

longer

exists:

host

unknown.