Specifications

Equalizer Installation and Administration Guide 205
latency The time over which a signal travels over a network, from the starting point to
the endpoint. See ping. See also CMP echo request and echo.
Layer 4 (L4) The transport layer; Layer 4 uses its rules and those of the previous three
layers to control accuracy of message delivery and service.which controls
accuracy of message delivery and service. See ISO/OSI model and Layer 7.
Layer 7 (L7) The application layer; Layer 7 uses its rules and those of the other layers to
control transmission of information from one application to another. Layer 7 is
the highest layer in the ISO/OSI model. See ISO/OSI model and Layer 4.
load A job that can be processed or transported once. See load balancing. See also
geographic load balancing and intelligent load balancing.
load balancing Moving a load from a highly-used resource to a resource that is used less often
so that operations are efficient. Equalizer balances loads over a wide physical
area or by using algorithms that assess options and real-time information. See
geographic load balancing and intelligent load balancing.
MX exchanger Mail exchanger; a fully qualified domain name to be returned if a server
receives a mail exchanger request.
name server A server that stores information about the domain name space.
NAT Network Address Translation; an Internet standard that defines the process of
converting IP addresses on a local-area network to Internet IP addresses. See
NAT subsystem.
NAT subsystem The Equalizer subsystem responsible for transferring connections to and from
the back-end servers.
netmask Address mask; a bit mask used to select bits from an Internet address for
subnet addressing. The mask is 32 bits long and selects the network portion
of the Internet address and one or more bits of the local portion.
Network Address Translation
(NAT)
See NAT.
network interface The place at which two or more networks connect and communicate with each
other. See interface. See external interface, interface, and internal interface.
network route See gateway.
OSI network A network that uses the International Organization for Standardization/Open
Systems Interconnection model. See ISO/OSI model, Layer 4, Layer 7, and
transport layer.
packet A group of data that is transmitted as a single entity.
passive FTP connection An Equalizer option that rewrites outgoing FTP PASV control messages from
the servers so that they contain the IP address of the virtual cluster rather
than that of the server. See FTP and PASV.
PASV Passive mode FTP; a mode with which you can establish FTP connections for
clients that are behind firewalls. See firewall, FTP, and passive FTP
connections.
pattern match A p
attern of ASCII or
hexadecimal data that filters data.
payload The set of data to be transmitted. A payload contains user information, user
overhead information, and other information that a user requests. A payload
does not include system overhead information. Also known as the mission bit
stream.
persistence The act of storing or retaining data for use at a later time, especially data that
shows the state of the network before processing resumes. See cookie and IP-
address-based persistence.