IBM TotalStorage 2109 M12, User Manual

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switch port. A port on a switch. Switch ports can be
expansion ports (E_ports), fabric ports (F_ports), or
fabric loop ports (FL_ports).
SWL. See short wavelength .
synchronous dynamic random access memory
(SDRAM). The main memory for the switch. Used for
volatile storage during switch operation.
T
Tachyon. A type of host bus adapter.
target. A storage device on a Fibre Channel network.
See also initiator .
TCP. See transmission control protocol .
tenancy. The time from when a port wins arbitration in
a loop until the same port returns to the monitoring
state. Also referred to as loop tenancy.
terminal serial port. The lower serial port on the
control processor card (CP card) of the director switch.
This port sends switch information messages and can
receive commands. Can be used to connect the CP
card to a computer terminal. Has an RS–232 connector
wired as a data terminal equipment (DTE) device, and
can be connected by serial cable to a data
communications equipment (DCE) device. The
connector pins 2 and 3 are swapped so that a
straight-through cable can be used to connect to a
terminal. The device name is ttyS0. Can also be
referred to as the console port. See also DCE port, DTE
port, and modem serial port .
throughput. The rate of data flow achieved within a
cable, link, or system. Usually measured in bits per
second (bps). See also bandwidth .
topology. As applies to fibre channel, the configuration
of the Fibre Channel network and the resulting
communication paths allowed.
translative mode. A mode in which private devices
can communicate with public devices across the fabric.
transmission character. A 10–bit character encoded
according to the rules of the 8b/10b algorithm.
Transmission control protocol (TCP). A
communications protocol used in the Internet and in any
network that follows the Internet Engineering Task Force
(IETF) standards for Internet protocol.
transmission word. A group of four transmission
characters.
trap (SNMP). The message sent by a simple network
management protocol (SNMP) agent to inform the
SNMP management station of a critical error. See also
simple network management protocol .
tunneling. A technique for enabling two networks to
treat a transport network as though it were a single
communication link or local area network (LAN).
Tx. Transmitted.
U
U. Unit of measure for rack-mounted equipment.
UART. Universal Asynchronous Receiver Transmitter.
UDP. See user datagram protocol .
ULP. See upper-level protocol .
ULP_TOV. See upper-level timeout value .
unicast. The transmission of data from a single source
to a single destination. See also broadcast and
multicast .
universal port (U_port). A switch port that can
operate as a generic port (G_port), expansion port
(E_port), fabric port (F_port), or fabric loop port
(FL_port). A port is defined as a U_port when it is not
connected or has not yet assumed a specific function in
the fabric.
U_port. See universal port .
upper-level protocol (ULP). The protocol that runs on
top of Fibre Channel. Typical upper-level protocols are
small computer system interface (SCSI), Internet
protocol (IP), HIPPI, and IPI.
upper-level timeout value (ULP_TOV). The minimum
time that a small computer system interface (SCSI)
upper-level protocol (ULP) process waits for SCSI
status before initiating ULP recovery.
user datagram protocol (UDP). A protocol that runs
on top of Internet protocol (IP) and provides port
multiplexing for upper-level protocols.
user flash. See compact flash .
V
VC. See virtual circuit .
VCCI. Voluntary Control Council for Interference
virtual circuit (VC). A one-way path between node
ports (N_ports) that allows fractional bandwidth.
W
WAN. See wide area network .
WDM. Wave
®
division multiplexing.
Glossary
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