The Transition to 10 Gigabit Ethernet Unified Networking: Cisco and Intel Lead the Way
4
e Transition to 10 Gigabit Ethernet Unied Networking: Cisco and Intel Lead the Way
Ethernet Enhancements
for Storage
IEEE DCB for Lossless Ethernet
To strengthen 10 Gigabit Ethernet as a
unied data center fabric, the IEEE has
standardized Ethernet enhancements to
support storage trac, including FCoE and
iSCSI. ese extensions, known collectively
as Data Center Bridging, or DCB, enable
better trac prioritization over a single
interface and an advanced means for
shaping trac on the network to decrease
congestion. In other words, DCB delivers a
lossless Ethernet fabric for storage trac.
FCoE: Enabling End-to-End Unified I/O
FCoE is a logical extension of Ethernet
that uses Fibre Channel’s network,
service, and protocol layers to carry data
packets over Ethernet’s physical and
data link layers. Fibre Channel’s unique
network-centered management model
has proven administrative capacity to
scale to thousands of end nodes in a data
center. e use of Fibre Channel’s higher
layers smoothes the transition to FCoE
because existing SAN-based applications
do not need to change to benet from
the performance and cost benets of
FCoE. e provisioning responsibilities,
now split between the server and storage
administrators, can be maintained in the
transition from Fibre Channel SANs to
Ethernet-based FCoE-powered SANs. In
addition, Ethernet links for FCoE trac
can be used in conjunction with native
Fibre Channel links for the same trac
ow. is capability enables existing Fibre
Channel SANs to be extended with new
servers or storage using converged LAN
and FCoE SAN links as needs change.
Many enterprises have extensive Fibre
Channel installations, and the availability
of software-based FCoE initiators makes
the Fibre Channel SAN easily accessible for
any server with a 10 Gigabit Ethernet port.
By allowing Fibre Channel technology
to use DCB-capable Ethernet, FCoE
eliminates the need for dedicated Fibre
Channel host bus adapters (HBAs),
reducing cabling and switch-port
requirements, while coexisting with existing
Fibre Channel infrastructures. e result
is a simplied data center infrastructure,
lower equipment and power costs, and
universal SAN connectivity across the data
center over the trusted Ethernet fabric.
INTRODUCING THE OPEN
FCOE ARCHITECTURE
e Open FCoE approach consists of
standard 10 Gigabit Ethernet adapters
and native OS-based FCoE initiators,
which together provide a robust, scalable,
and high-performance server connectivity
option without expensive, proprietary
hardware. As shown in Figure 4, Open
FCoE implements the complete Fibre
Channel protocol in the OS kernel. It
provides libraries for dierent system-
level implementations, allowing vendors
to implement dataplane functions of
the FCoE stack in hardware to deliver
optimum performance.
Open FCoE: Momentum
in the Linux Community
e Linux* community accepted the
Open-FCoE project in November 2007
with the goal of accelerating development
of a native FCoE initiator in the
Linux kernel. e industry responded
enthusiastically, and today there are
more than 190 active participants in the
community who are contributing code,
providing review comments, and testing
the Open FCoE stack. To date,
the Open FCoE source web site
(www.open-fcoe.org) has received more
than 20,000 hits. Open industry standards
and open source technology play signicant
roles in the modern data center, reducing
R&D investment and enabling access
to a multivendor supply chain that is
designed for heterogeneous interoperability,
ultimately resulting in greater choice and
lower equipment costs.
e Open FCoE approach oers a number
of advantages in accessibility and ease of use:
• Accessibility. e Open FCoE approach
makes Fibre Channel SAN access available
to any server with a DCB-capable 10
Gigabit Ethernet adapter installed. IT
departments can standardize on these
adapters to simplify server connectivity
across multiple use cases. With FCoE
support integrated into the OS, Fibre
Channel SAN access will become
readily available across these converged
networks and even more accessible when
10 Gigabit Ethernet LOM technology
becomes pervasive.
FCoE data path offloads
Ethernet MAC
Ethernet PHY
Figure 4. Overview of the Open FCoE
initiator solution.
Open FCoE Solution
Operating System
Device Driver
Application I/O
SCSI storage interface
Fibre Channel protocol
FCoE transport protocol