Fibre Channel Data Constructs Ordered Sets and Primitives
Primitive Signals
• Control signals:
– R_RDY – VC_RDY – OPN – DHD – CLS –MRK – SYN
Receiver Ready
Virtual Circuit Ready (Class 4) Open Port
Dynamic Half-Duplex Close all opened ports Mark
Clock synchronization
Frame
R_RDY
Initiator Target
Arbitrated Loop only
The other types of Primitive Signal are called control signals. These are simple commands that are sent between ports primarily to perform flow control functions:
R_RDY (Receiver Ready) is sent by a port when the port is ready to receive data. R_RDY is used in buffer-to-buffer flow control.
VC_RDY (Virtual Circuit Ready) is used for flow control in Class 4 virtual-circuit connections.