HP 2605dtn - Manual (Page 98)

TCP/IP
This section is intended to provide information to help you gain a basic understanding of TCP/IP.
Similar to a common language that people use to communicate with each other, TCP/IP
(Transmission Control Protocol/Internet Protocol) is a suite of protocols designed to define the way
computers and other devices communicate with each other over a network.
TCP/IP is rapidly becoming the most used set of protocols. The main reason this is happening is the
fact that the Internet is based on TCP/IP. If you have a network that you wish to connect to the
Internet, you must be using TCP/IP to communicate.
Internet Protocol (IP)
When information is sent across the network, the data is broken down into small packets. Each
packet is sent independently of one another. Each packet is encoded with IP information, such as the
IP address of the sender and receiver. IP packets can be routed over routers and gateways, devices
that connect a network with other networks.
IP communications is connectionless. When IP packets are sent, there is no guarantee that they
arrive at their destination in the proper sequence. That task can be performed by higher level
protocols and applications thereby allowing IP communications to be efficient.
Each node or device that will communicate directly onto the network requires an IP address.
Transmission Control Protocol (TCP)
TCP handles breaking the data into packets and recombining the packets on the receiving end by
providing a connection-oriented, reliable, and guaranteed delivery service to another node on the
network. When data packets are received at their destination, TCP calculates a checksum for each
packet to verify the data is not corrupt. If the data in the packet has been corrupted during
transmission, TCP discards the packet and requests that the packet be resent.
User Datagram Protocol (UDP)
UDP provides similar services to TCP. However, UDP does not acknowledge data receipt and
supports request/reply transactions with no added reliability or guarantee of delivery. UDP is used
when acknowledgment and reliability are not required, such as during a “discovery broadcast.”
IP address
Every host (workstation or node) on an IP network requires a unique IP address for each network
interface. This address is a software address that is used to identify both the network and specific
hosts located on that network. Each IP address can be divided into two separate parts: the network
portion and the host portion. It is possible for a host to query a server for a dynamic IP address each
time the device boots up (for example, using DHCP and BOOTP).
NOTE When assigning IP addresses, always consult the IP address administrator. Setting
the wrong address can disable other equipment operating on the network or interfere with
communications.
86 Chapter 8 Networking ENWW