CS558 Sylabus
Preliminaries on the TCP client
Reminder:
identifying
a TCP Connection
Remember
that a
TCP connection
is
identified
by:
The
4 values
:
(srcIP, srcPort#,
destIP, destPort#
)
And
(
destIP, destPort#
, srcIP, srcPort#)
identifies a
different
TCP connection
Meaning:
The
control messages
(in the
examples
) will
only
apply
to:
The
TCP connection
that is
identified
by the
given
(srcIP, srcPort#, destIP, destPort#)
values !!!
The
Server's
IP address and port#
Assumption:
The
client
knows
:
The
IP address
and
TCP port#
of the
Server
!!!!
This is
essential
before the
client
can
initiate
the
TCP connection
Example:
Web server:
The
URL
(e.g.:
www.mathcs.emoru.edu
) provides the
IP address
of the
server
The
port#
of a
webserver
is by
default
TCP port #80
The
Client's
IP address and TCP port#
The
Client's
IP address
:
The
Client
can
find
the
IP address
on it's
own
computer
The
Client's
TCP port#
:
The
client
can pick an
arbitrary
(unused)
TCP port#
to
establish
a
TCP connection
....
Summary
At the
start
of the
TCP connection establishment
protocol
, the
client
knows
:
The
server's
IP address
and
TCP port #
The
client's
own
IP address
and
TCP port #