Data Center I/O Consolidation - Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual

Data Center I/O Consolidation

New Technologies in the Cisco Nexus 5000 Series
a lossless transport layer; as a data storage protocol, it is unacceptable to lose a single data packet. Native
Fibre Channel implements a lossless service at the transport layer using a buffer-to-buffer credit system.
For FCoE traffic, the Ethernet link must provide a lossless service. Ethernet links on Cisco Nexus 5000 Series
switches provide two mechanisms to ensure lossless transport for FCoE traffic: link-level flow control and
priority flow control.
IEEE 802.3x link-level flow control allows a congested receiver to signal the far end to pause the data
transmission for a short period of time. The pause functionality is applied to all the traffic on the link.
The priority flow control (PFC) feature applies pause functionality to specific classes of traffic on the Ethernet
link. For example, PFC can provide lossless service for the FCoE traffic and best-effort service for the standard
Ethernet traffic. PFC can provide different levels of service to specific classes of Ethernet traffic (using IEEE
802.1p traffic classes).
Data Center I/O Consolidation
I/O consolidation allows a single network technology to carry IP, SAN, and IPC traffic. FCoE is the single
network technology that allows I/O consolidation. The upper Fibre Channel layers are unchanged, so the Fibre
Channel operational model is maintained. FCoE network management and configuration is similar to a native
Fibre Channel network.
Cisco Nexus 5000 Series switches use FCoE to carry Fibre Channel and Ethernet traffic on the same physical
Ethernet connection between the switch and the server. At the server, the connection terminates to a converged
network adapter (CNA). The adapter presents two interfaces to the server's operating system (OS): one Ethernet
NIC interface and one Fibre Channel host bus adapter (HBA) interface.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
2 OL-16597-01