TCP/IP
Protocol Suite
The
Microsoft TCP/IP protocol
suite
enables enterprise networking and connectivity on Windows 2003-based
computers. A suite is created by a vendor or organization to
customize a protocol stack for its requirements. Therefore, a
protocol suite is a set of protocols designed and built as
complementary parts of a complete, smoothly functioning set.
The
TCP/IP protocol suite includes six core protocols and a set of
utilities. The six core protocols—TCP, UDP, IP, ICMP, IGMP, and
ARP—provide a set of standards for communications between computers
and for connections between networks. All applications and other
protocols in the TCP/IP protocol suite rely on the basic services
provided by these core protocols.
Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP) is a required TCP/IP standard
protocol that provides a reliable, connection-oriented data delivery
service between only two computers. Such a communication is known as
a unicast. In connection-oriented communication, the connection must
be established before data can be
transmitted between the two computers. After the connection is
established, data is transmitted over this single
connection only. Connection-oriented communication is also referred
to as reliable communication because it guarantees the delivery of
the data at the destination.
On
the source computer, TCP organizes the data to be transmitted into
packets. On the destination computer, TCP reorganizes the packets to
recreate the original data.
Data
Transmission Using TCP
TCP
transmits packets in groups to increase efficiency. It assigns a
sequence number to each packet and uses an acknowledgment to verify
that the destination computer has received a group of packets. If
the destination
computer does not return an acknowledgment for each group of packets
sent within a specified period of time, the source computer
retransmits the data. In addition to adding the sequencing and
acknowledgement information to the packet, TCP also adds the port
information for both the source and the destination applications.
The source computer uses the destination port to direct the packet
to the proper application at the destination computer, and the
destination computer uses the source port to return information to
the correct
source application.
Three-Way Handshake
Because TCP is a reliable protocol, two computers using TCP for
communication must establish a connection before exchanging data.
This connection is a virtual connection and is known as a
session.
Two computers
using TCP establish a connection, or TCP session, through a process
known as a three-way handshake. This process synchronizes sequence
numbers and provides other information needed to establish the
session.
The
three-way handshake is a three-step process:
1.
The source computer initiates the connection by transmitting the
session information, including the sequence number and size of the
packet.
2.
The destination computer responds with its session information.
3.
The source computer agrees with and acknowledges the received
Information.
