Technical data

170 Agilent Connectivity Guide
7TCP/IP Network Basics
data from the Transport Layer protocols of other hosts. Hosts can be on
the same local network or on a remote network. The Transport Layer
has two protocols:
• Transmission Control Protocol (TCP)
• User Datagram Protocol (UDP)
Transmission Control Protocol (TCP) Transmission Control
Protocol (TCP) is the protocol that connects the sending host and the
receiving host to each other. TCP provides the connection as packets are
moved between hosts having the conversation. Every packet has a TCP
header that includes
sequence numbers, acknowledgement numbers,
address information, and other information. If packets get out of order
enroute from the source to the destination, the sequence number allows
the packets to be reassembled in the correct order.
As each packet is sent from the source host, an acknowledgement of
receipt is sent by the destination host within a specified time. If the
acknowledgement is not sent within this time, the sender re-sends the
packet.
If the receiver gets the packet in a damaged condition, the packet is
discarded and the receiver sends no acknowledgement. In this case,
since an acknowledgement was not received in the specified time, the