iTP Secure WebServer System Administrator's Guide (Version 7.0)

Glossary
iTP Secure WebServer System Administrator’s Guide—523346-012
Glossary-6
TCP Delayed Acknowledgements
on another. It is connection-oriented, in the sense that before transmitting data
participants must establish a connection. Software implementing TCP usually resides
on the operating system and uses the Internet Protocol (IP) to transmit information
across the Internet. It is possible to terminate (shut down) one direction of flow across
a TCP connection, leaving a one-way (simplex) connection. The Internet protocol suite
is often referred to as TCP/IP because TCP is one of the two most fundamental
protocols.
TCP Delayed Acknowledgements. For every data packet received, TCP/IP sends an
'ACK' packet for synchronization purposes. This is done in order to ensure that the
data packet has reached its destination. If anything goes wrong with the data packet
during transmission, the acknowledgement packet 'ACK' will not be received at the
sender's end. In this condition, the data packet will be re-transmitted. There is a fair
possibility that these 'ACK' packets may cause the network congestion. TCP Delayed
Acknowledgments is a feature introduced into TCP which uses the Delayed ACK
Algorithm, by default with a delay timer of 200 milliseconds. It does not send an ACK
right away. The hope is to have data ready in that time frame of 200 milliseconds.
Then, the 'ACK' can be sent (piggy-backed) along with a data segment.
TELNET. The Internet standard protocol for remote terminal connection service. TELNET
allows a user at one site to interact with remote timesharing systems at another site
just as if the user’s terminal is connected directly to the remote machine. That is, the
user invokes a TELNET application program that connects to a remote machine,
prompts for a login ID and password, and then passes keystrokes from the user’s
terminal to the remote machine and displays output from the remote machine on the
user’s terminal.
Unicode. The 16-bit character encoding used by Java for the char and java.lang.String data
types.
URL. Uniform Resource Locator.
wait mode. In the NonStop operating system, the mode in which the called procedure waits
for the completion of an input/output (I/O) operation before returning a condition code
to the caller. Compare nowait mode
.
Web Container. A Java run-time environment that manages the lifecycle of servlets and
JSP.
Web clients. Programs that execute on IBM-compatible PC, Apple Macintosh, or Unix
platforms, among others. They provide a graphic user interface (GUI) for access to
documents and programs on the Web. A Web browser is the most familiar example of
a Web client.