Fibre Channel Primer

42 Fibre Channel: Connection to the Future
A node may reserve up to 256 concurrent Class 4 connections.
Separate functions of Class 4 are setup of the QoS parameters and
the connection itself.
When a Class 4 connection is active, the switch paces frames
from the source node to the destination node. Pacing is the mechanism
used by the switch to regulate available bandwidth per VC. This level
of control permits congestion management for a switch and guarantees
access to the destination node. The switch multiplexes frames
belonging to different VCs between the same or different node pairs.
Class 4 service provides in-order delivery of frames.
Class 4 flow control is end-to-end and provides guaranteed
delivery. Class 4 is ideal for time-critical and real-time applications
like video.
Class 6: Uni-Directional Connection Service with Multicast
and Preemption
Class 6 is similar to Class 1, providing uni-directional connection
service. However, Class 6 also provides reliable multicast and
Figure 6.6 Class 6 provides dedicated one-to-many service
Real Time
Sensor
i.e., Radar
Video
Server
Radar Displays
Video
Distribution
Network
Switch