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EF2915 Series User Guide 83
Chapter
Glossary
7
This section describes the terminology introduced in this guide, as well as related terms
used in telecommunications technology and standards.
Arbitrated Loop
A Fibre Channel topology that defines the connections between hosts and devices. Two or
more ports can be interconnected, but only two at a time can communicate. The loop
supports up to 126 devices and one fabric attachment on one loop.
Arbitrated Loop Physical Address
An 8-bit value that identifies a device in an arbitrated loop. This value is always the last 8
bits of the 24-bit address field.
Arbitration
The process that facilitates orderly access to a shared-loop technology.
Buffer to Buffer Credit
The (Fibre Channel) flow control system that provides pacing of the traffic load in order to
prevent frame loss. In effect, it determines how many frames can be sent to a recipient. A
credit represents a device’s ability to accept an additional frame. If no credits are issued by
a recipient to a sender, the sender cannot send to that recipient.
Class 2
A connectionless Class of Service that allows streams of frames to be sent to different
destinations quickly and requires acknowledgment of frame delivery. It is generally used in
applications requiring a high degree of data integrity at the transport level.
Class 3
A connectionless Class of Service (sometimes called a “datagram”) that does not require
acknowledgment of frame delivery. Class 3 provides higher performance with less
overhead, but can be less reliable, since under highly congested conditions, it may discard
frames.
Destination WWN
The world-wide name that identifies the port that will receive the frame.
Discovery
In a fabric network, the process of identifying other devices in the network. See also Name
Server and Loop Initialization .
Exchange
A set of related, bidirectional sequences that represents a complete I/O operation. See also
Sequence .