Understanding iWarp

Understanding iWARP:
Delivering Low Latency to Ethernet
For years, Ethernet has been the de facto standard local area network (LAN) technology for connecting users
to each other and to network resources. Low cost and increasing Ethernet data rates have simplied growth
for existing data networking applications and removed the wire-speed barriers to deployment in storage and
clustering environments. However, for certain types of applications such as large-scale nancial services, cloud
computing, and high-performance computing (HPC), Ethernet’s inherent latency and limited message-processing
rates have presented unacceptable performance barriers.
As the data center evolves toward a more virtualized model, with a higher degree of abstraction applied to the
network and servers, Internet Wide Area RDMA Protocol (iWARP) has emerged as an important enabler to help
businesses get the full network throughput benets of the latest 10 Gigabit Ethernet (10GbE) technologies.
What is iWARP?
iWARP delivers converged, low-latency fabric services to data centers
through Remote Direct Memory Access (RDMA) over Ethernet.
The key iWARP components that deliver low-latency are as follows:
•KernelBypass. Removes the need for context switching from
kernel-space to user-space
•DirectDataPlacement.Eliminates intermediate buffer copies
by reading and writing directly to application memory
•TransportAcceleration.Performs transport processing on the
network controller instead of the processor
The iWARP specication, maintained by the Internet Engineering Task
Force (IETF), supports transmissions over TCP and is implemented on
top of IP networks using an existing Ethernet infrastructure.
CapitalizingontheBenefitsofiWARP
NetEffect™ Ethernet Server Cluster Adapters from Intel use
iWARP technology to decrease Ethernet’s latency for storage and
clustering networks. By addressing the key sources of Ethernet
overhead, iWARP provides these benets:
• Fabricconsolidation. With iWARP technology, a true unified
network of LAN, SAN, and RDMA traffic can pass over a single
wire. Moreover, application and management traffic can be
converged, reducing cables, ports, and switches.
• IP-basedmanagement. Network administrators can use
standard IP tools to manage traffic in an iWARP network, taking
advantage of existing skill sets and processes to reduce the
overall cost and complexity of operations.
• Nativeroutingcapabilities. Because iWARP uses Ethernet
and the standard IP stack, it can use standard equipment and be
routed across IP subnets using existing network infrastructure.
• Existingswitches,appliances,andcabling. The flexibility of
using standard TCP/IP Ethernet to carry iWARP traffic means
that no changes are required to Ethernet-based network equipment.
iWARPBringsBenefitstotheDataCenter
NetEffect Ethernet Server Cluster Adapters from Intel use
iWARP to virtually eliminate processor overhead associated with
Ethernet networking. TCP/IP continues to be the core protocol
stack as data centers transition to cloud computing, and iWARP
allows LAN, SAN, RDMA, and standard IP management trafc
to pass over a single wire in TCP/IP networks. All of this trafc
is natively routable and uses standard Ethernet switches, for a
simplied, cost-effective holistic solution.
Because of these benets, server vendors are increasingly
standardizing on iWARP for clustered systems. NetEffect
Ethernet Server Cluster Adapters from Intel fully implement
iWARP extensions to TCP/IP, helping to bring dramatic
improvements in networking performance at low cost using
existing equipment and processes.
TECHNOLOGYBRIEF
NetEffect™EthernetServerClusterAdapters
Internet Wide Area RDMA Protocol (iWARP)