Glossary

buffer-to-buffer credit

BB_Credit. (1) The maximum number of receive buffers allocated to a transmitting node port (N_Port) or fabric port (F_Port). Credit represents the maximum number of outstanding frames that can be transmitted by that N_Port or F_Port without causing a buffer overrun condition at the receiver. (2) The maximum number of frames a port can transmit without receiving a receive ready signal from the receiving device. BB_Credit can be adjustable to provide different levels of compensation.

bypassed port

If a port is bypassed, all serial channel signals route past the port. A device attached to the port cannot communicate with other devices in the loop.

byte

Abbreviated as B. A byte generally equals eight bits, although a byte can equal from four to ten bits. A byte can also be called an octet See also octet.

C

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.

cascade

Linking two or more Fibre Channel switches to form a larger switch or fabric. The switched link through fiber cables attached between one or more expansion ports (E_Ports). See also expansion port.

CBY

Channel operations running in byte mode. This occurs when a channel is attached to a converter and specifies the I/O operation mode for the channel path under the I/O configuration program (IOCP) channel path identifier (CHPID) statement ‘Type’ parameter. Contrast with CVC.

cell

In S/390 mode, in a port address matrix, a cell is the intersection point between a horizontal port address and a vertical port address. A selected cell is indicated by the cell cursor.

chained

Two directors or switches that are physically attached.