director 2/64 service manual

director 2/64 service manual Glossary–3
Glossary
broadcast frames
Data packet, also known as a broadcast packet, whose destination address specifies all
computers on a network.
buffer
Storage area for data in transit. Buffers compensate for differences in processing speeds
between devices. See also buffer-to-buffer credit.
buffer-to-buffer credit (BB_Credit)
Indicates the maximum number of frames a port can transmit without receiving a receive
ready signal from the receiving device.
call-home
Product feature which enables the HAFM server to automatically contact a support center and
report system problems. The support center server accepts calls from the HAFM server, logs
reported events, and can notify one or more support center representatives.
channel
Point-to-point link that transports data from one point to the other.
channel path
A single interface between a central processor and one or more control units along which
signals and data can be sent to perform I/O requests.
channel path identifier
In a channel system, a value assigned to each installed channel path of the system that
uniquely identifies that path to the system.
channel wrap test
A diagnostic procedure that checks S/390 host-to-director connectivity by returning the output
of the host as input. The test is host-initiated and transmits Fibre Channel frames to a director
port. A director port enabled for channel wrapping echoes the frame back to the host.
class of Fibre Channel service
Defines the level of connection dedication, acknowledgment, and other characteristics of a
connection. Class F, Class 2, and Class 3 services are supported.
Class F Fibre Channel service
Used by switches to communicate across interswitch links (ISLs) to configure, control, and
coordinate a multi-switch fabric.