Industrial Communication Systems

Transmission Control Protocol—TCP 61-11

e error correction is implemented by establishing a time-out counter for each segment sent. If the

acknowledgment

is

received,

then

the

particular

and

all

preceding

counters

and

the

segments

are

dis-

posed.

If the counter reaches time-out, then the segment is resent and the timer is reset.

A

duplicate segment

can

be

created

if

the

acknowledgment

segment

is

lost

or

is

delayed

too

much.

Since

data

are

reassembled

into

a

byte-stream

at

the

destination,

data

from

the

duplicate

segment

is

already

in the buer. e duplicate segment is discarded. No acknowledgment is sent.

An

out-of-order segment

is

stored

but ...