HP Surestore Director FC-64 Command Line Interface User's Guide

112 Glossary
BB_Credit
Also kno wn as Buffer-to-Buffer Credit. The maximum number o f frames a po rt can
transmit without receiving a receive ready signal from the receiving device.
blocked port
Devices communicating with the port are prevented from logging into the director or
communicating with other devices attached to the director. A blocked port
continuously transmits the offline sequence.
buffer
A storage area for data in transit. Buffers compensate for differences in processing
speeds between devices. See also BB_Credit.
C
channel
A point-to-point link that transpo rts data from o ne point to the other.
class of Fibre Channel service
Defines the level of connection dedicatio n, acknowledgment, and o ther characteristics
of a connection.
Class F Fibre Channel service
Used by switc hes to c o mmunic ate acro ss interswitc h links (ISLs) to co nfigure, co ntrol,
and coordinate a multiswitch fabric.
Class 2 Fibre Channel service
Provides a connectionless (not dedicated) service with notification of delivery or
nondelivery between two N_Ports.
Class 3 Fibre Channel service
Provides a connectionless (not dedicated) service without notification of delivery or
nondelivery between two N_Ports. Also known as datagram.