Storage Networking Architectures Storage Transport Protocols
Channels and Networks I/O Channel (e.g. SCSI)
Network (e.g. Ethernet)
x Few devices x Static addressing Low latency x Short distances
Hardware-based delivery management
Many devices Dynamic addressing x High latency Long distances
x Software-based delivery management
I/O bus (channel) architecture: A channel is a directly attached and well-structured mechanism designed to transmit data between a host and a small number of devices in a well-known configuration. Because channels are static and well-structured, data can be routed between devices with minimal delays, providing low latency. Channels generally use a parallel architecture. This architecture can support high speeds, but only short distances. Due to the static and well-structured nature of channels, they perform only minimal decision-making tasks. These tasks can be performed by hardware, which ensures a minimal load on the host’s CPU and provides rapid delivery.