Intel Ethernet Cloud White Paper

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The daily reality for IT organizations is
that they must accommodate the needs
of their customers that conduct business
with IT’s data center assets. In the case
of a private cloud, the IT customers are
business units, such as engineering,
sales, marketing, and nance, within
the company. Those customers often have
different QoS requirements, represented
in Figure 5 as bronze (low), silver
(medium), and gold (high).
QoS can be divided into two areas:
“on the wire” and “at the guest level.”
In this context, “on the wire” refers
to QoS considerations related to IT’s
responsibility to guarantee virtual
network services such as storage,
management, and applications. This
includes the management of multiple
trafc classes that exist on a single
physical port and that have individual
requirements in terms of latency, priority,
and packet delivery.
DCB is the set of IEEE open standards
that define how these traffic classes are
implemented and enforced on a single wire:
• Data Center Bridging eXchange (DCBX)
• Enhanced Transmission Selection (ETS)
• Priority Flow Control (PFC)
• Quantized Congestion Notification (QCN)
The use of DCB is preferable as a means
of allocating guaranteed amounts of
bandwidth to specic trafc classes, as
opposed to multiple physical ports or
statically assigning bandwidth. Solutions
that statically assign bandwidth typically
do not allow the bandwidth to exceed
the set limit, even if there is available
bandwidth on the wire. DCB provides
an advantage here because it limits the
maximum bandwidth only in cases of
contention across trafc classes.
The “guest level” aspect of QoS involves
different levels of service for customers
and groups, largely by means of
bandwidth limiting and services within the
VMVM
QoS Level: Silver
Management
Virtual Switch
Intel® VT-c
Console
Aggregation
10GbE Switch
Aggregation
GbE Switch
Hypervisor X
Physical Host 1
Aggregation
10GbE, FCoE Switch
iSCSI, Fibre
Channel SAN
with 10GbE
Storage Processor
10GbE
Server
Adapter
LAN
Virtual Switch
Storage
Initiators
Intel® VT-c
GbE
LOM
10GbE
Server
Adapter
Management
Virtual Switch
Hypervisor Y
Physical Host N
LAN
Virtual Switch
Storage
Initiators
GbE
LOM
Intel® VT-c
10GbE
Server
Adapter
Intel® VT-c
10GbE
Server
Adapter
VM VM VM
QoS Level: Gold
VM
QoS Level:
Silver
VM
QoS Level:
Bronze
VM VM
QoS Level: Gold
VM
QoS Level:
Bronze
WAN
eg
ation
gation
o
n
ch
. Network policy, traffic shaping, and scheduling enable robust quality-of-service support.
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