Datasheet

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CHAPTER 1 VMware VSphere 4 OVerView
Bidirectional Traffic Shaping
vNetwork Standard Switches allow you to set up traffic shaping for egress or transmit (from virtual
machine to network) traffic. vDS expands this capability to include bidirectional traffic shaping.
Both egress (from virtual machine to network) and ingress (from network into virtual machine)
traffic-shaping policies can now be applied on DV port group definitions. You can use the fol-
lowing three characteristics to define traffic-shaping policies:
Average bandwidth
•u
Peak bandwidth•u
Burst size•u
You can leverage traffic shaping to limit the traffic to or from a virtual machine or group
of virtual machines to protect either a virtual machine or other traffic in an over-subscribed
network.
Third-Party Virtual Switch Support with the Cisco Nexus 1000V Series Virtual Switch
The vDS includes support for third-party distributed virtual switches. Cisco collaborated with
VMware to leverage this extensibility to develop the Cisco Nexus 1000V Series virtual switch.
Both the Cisco Nexus 1000V Series virtual switch and the VMware vNetwork Distributed
Switch use the same distributed switching model.
Virtual Ethernet modules (VEMs) Each ESX host implements VEMs, which are the switch-
ing data planes, and provide the frame-forwarding capabilities. These VEMs leverage the ESX
host APIs and can support the same physical NICs and hardware compatibility list (HCL) as
the VMware Standard Switch and vNetwork Distributed Switch.
Virtual supervisor modules (VSMs) The Cisco NX-OS operating system implements VSMs.
They provide the control plane function for the VEMs and can exist as a guest VM or stand-
alone appliance. VSMs allow you to use the familiar Cisco command-line interface (CLI) for
management and configuration. You can also use vSphere Client to communicate with VSMs
and vCenter Server for optional management and configuration.
The Cisco Nexus 1000V offers an expanded feature set compared to the VMware vNetwork
Distributed Switch and is similar to that provided by the physical Cisco Catalyst and Nexus
switches. You can find more information on the Cisco Nexus 1000V at http://cisco.com/go/
nexus1000v.
ne t w o r k Pe r F o r M a n c e a n d Sc a l a b i l i t y
vSphere includes several performance enhancements to the network stack. These enhance-
ments come in two ways: support for various offload technologies and optimizations to the
existing network stack processing. It is a common performance optimization practice to offload
various network processing tasks to reduce the CPU overhead associated with processing net-
work I/O. The VMXNET3 network adapter supports performance offload technologies such as
TCP Segmentation Offloading, TCP/IP Checksum Offload, and Large Receive Offload, as well
as other optimizations like jumbo frames. vSphere 4 also includes optimizations to the network
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