Technical data

Glossary-12 Fabric OS Administrator’s Guide
Publication Number: 53-0000518-09
NOS Not operational. The NOS primitive sequence is transmitted to indicate that the FC_Port transmitting
the NOS has detected a link failure or is offline, waiting for the offline sequence (OLS) to be received.
NS Name Server. The service provided by a fabric switch that stores names, addresses, and attributes
related to Fibre Channel objects. Can cache information for up to 15 minutes. Also known as “Simple
Name Server” or as a “directory service.” See also “SNS”.
Nx_Port A node port that can operate as either an N_Port or NL_Port.
O
OLS Primitive sequence offline.
ON Offline notification. Refers to an ELS field that appears in portlogdump command output.
OPN Open primitive signal. Applies only to arbitrated loop; sent by an L_Port that has won the arbitration
process to open communication with one or more ports on the loop.
ordered set A transmission word that uses 8B/10B mapping and begins with the K28.5 character. Ordered sets
occur outside of frames and include the following items:
Frame delimiters. Mark frame boundaries and describe frame contents.
Primitive signals. Indicate events.
Primitive sequences. Indicate or initiate port states.
Ordered sets are used to differentiate Fibre Channel control information from data frames and to
manage frame transport.
originator The Nx_Port that originated an exchange.
out-of-band Transmission of management protocol outside of the Fibre Channel network, usually over Ethernet.
OX_ID Originator ID. Refers to the exchange ID assigned by the originator port.
P
parallel The simultaneous transmission of data bits over multiple lines.
path selection The selection of a transmission path through the fabric. Brocade switches use the FSPF protocol. See
also “FSPF”.
payload A Fibre Channel frame has a header and a payload. The payload contains the information being
transported by the frame; it is determined by the higher-level service or FC_4 upper-level protocol.
There are many different payload formats, based on protocol and size of truck bed.
Performance
Monitoring
A Brocade SilkWorm switch feature that monitors port traffic and includes frame counters, SCSI read
monitors, SCSI write monitors, and other types of monitors.
phantom
address
An AL_PA value that is assigned to a device that is not physically in the loop. Also known as "phantom
AL_PA."