HP-UX IPQoS A.01.00 Administrator's Guide (October 2005)

Glossary 131
Glossary
adapter block In the context of an HP-UX
IPQoS configuration file, defines a specific
adapter controlled by HP-UX IPQoS, and the
policies it uses.
bandwidth The amount of data that can be
sent over a network in a fixed amount of
time. Typically expressed in bits per second
(or in Kb/s or Mb/s).
bandwidth limiting Lowering the rate at
which data can be sent; preventing a traffic
source from sending as fast as it otherwise
can.
classifier A device that selects packets
based on the aspects of those packets,
according to defined rules.
conditioner A device that performs control
functions including metering, marking,
policing and shaping. It does this by marking
packets with the appropriate DSCP, and by
altering characteristics of traffic streams to
bring them into compliance with traffic
profiles.
Differentiated Services (DS) The
differentiated services framework as defined
in RFC 2475.
Differentiates Services Codepoint
See DSCP.
DiffServ A shorthand term for
Differentiated Services.
DS behavior aggregate A collection of
packets with the same DSCP value, crossing
a network device in a particular direction.
DS-compliant A node or device that is
enabled to support DiffServ functions and
behaviors as defined in RFC 2475.
Differentiated Services Codepoint
(DSCP) A specific value of the codepoint
portion of the DS field. Recommended
codepoints map to specific, standardized
PHBs. Multiple codepoints can map to the
same PHB.
DS field The leftmost 6-bits of the TOS field
for IPv4 packets and the leftmost 6-bits of
the Traffic Class field for IPv6 packets.
expansion The process in HP-UX IPQoS
where, if a host name or the service name
specified as a filter attribute resolves to
more than one address or port, the filter is
automatically duplicated for each address or
port.
filter block In the context of an HP-UX
IPQoS configuration file, defines a specific
filter against which to match traffic. A
packet matches the filter only if all specified
traffic class attributes match those of the
packet.
implicit default flow The behavior
assigned to packets that do not match any
specified filter. The behavior assignment in
this case is setting 80Kbps as the
reservation bandwidth, no set maximum
bandwidth, and no marking actions
specified.
marker A device that sets the DSCP of a
packet based on predefined rules.