IBM SAN16B-2 - TotalStorage Express Model Switch User And Service Manual page 73

Challenge Handshake Authentication Protocol
(CHAP). (1) An authentication protocol that protects
against eavesdropping by encrypting the user name and
password. (2) Allows remote servers and clients to
securely exchange authentication credentials.
chassis. The metal frame in which the switch and
switch components are mounted.
CIM. See Common Information Model
circuit. An established communication path between
two ports. Consists of two virtual circuits capable of
transmitting in opposite directions. See also link.
class 1 service. The class of frame-switching service
for a dedicated connection between two communicating
ports (also called "connection-oriented service").
Includes acknowledgement of frame delivery or
nondelivery.
class 2 service. A connectionless class of
frame-switching service that includes acknowledgement
of frame delivery or nondelivery.
class 3 service. A connectionless class of
frame-switching service that does not include
acknowledgement of frame delivery or nondelivery. Can
be used to provide a multicast connection between the
frame originator and recipients, with acknowledgement
of frame delivery or nondelivery.
class 4 service. A connection-oriented service that
allows fractional parts of the bandwidth to be used in a
virtual circuit.
class 6 service. A connection-oriented multicast
service geared toward video broadcasts between a
central server and clients.
class F service. The class of frame-switching service
for a direct connection between two switches, allowing
communication of control traffic between the E_Ports.
Includes acknowledgement of data delivery or
nondelivery.
class of service. A specified set of delivery
characteristics and attributes for frame delivery.
CLI. See command line interface.
client. A system or process that is dependent on
another system or process (usually called the server) to
provide it with access to data, services, programs, or
resources.
comma. A unique pattern (either 1100000 or 0011111)
used in 8b/10b encoding to specify character alignment
within a data stream.
command line interface (CLI). Interface that depends
entirely on the use of commands, such as through
Telnet or simple network management protocol (SNMP),
and does not involve a graphical user interface.
Common Information Model (CIM). An
implementation-neutral, object-oriented schema for
describing network management information. The
Distributed Management Task Force (DMTF) develops
and maintains CIM specifications.
community (SNMP). A relationship between a simple
network management protocol (SNMP) agent and a set
of SNMP managers that defines authentication, access
control, and proxy characteristics.
compact flash. Flash (temporary) memory that is
used in a manner similar to hard disk storage. It is
connected to a bridging component that connects to the
PCI bus of the processor. Not visible within the
processor's memory space.
control processor (CP). The central processing unit
that provides all control and management functions in a
switch.
control processor card (CP card). The central
processing unit of the director/switch, which contains
two control processor (CP) card slots to provide
redundancy. Provides Ethernet, serial, and modem ports
with the corresponding light-emitting diodes (LEDs).
CP. See control processor.
CP card. See control processor card.
CPU. See central processing unit.
credit. When applied to a switch, the maximum
number of receive buffers provided by a fabric port
(F_port) or fabric loop port (FL_port) to its attached
node port (N_port) or node loop port (NL_port),
respectively, such that the N_port or NL_port can
transmit frames without over-running the F_port or
FL_port.
CRU. See customer replaceable unit
CSA. Canadian Standards Association.
customer replaceable unit (CRU). An assembly that
is replaced in its entirety by a customer when any one
of its components fails. In contrast, a field replaceable
unit (FRU) can only be replaced by a qualified service
representative.
cut-through. A switching technique that allows the
route for a frame to be selected as soon as the
destination address is received. See also route.
D
data rate. The rate at which data is transmitted or
received from a device. Interactive applications tend to
require a high data rate, while batch applications can
usually tolerate lower data rates.
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Glossary