Effects of virtualization and cloud computing on data center networks

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Figure 2: Architectural overview of VDI with blade servers, storage, and HP Virtual SAN Appliance (VSA)
included for the infrastructure.
For example, a VDI could let you access a device based on a Microsoft Windows Vista OS, leave for
the evening, and come back the next workday to a Microsoft Windows 7-based device—with all your
data, customized desktop settings, and customized application settings intact.
A standard VDI configuration would use rack-based servers distributed across the data center with
Top of Rack (ToR) switches at the network edge. Network traffic from each rack of the distributed
servers (for example, Microsoft Exchange servers, Active Directory servers, user application servers,
or the VDI servers) would travel to its own ToR switch before traveling to the network core and then
out to the client.
But HP has designed VDI reference architectures on HP BladeSystem with Virtual Connect hardware.
This keeps the majority of network traffic inside the Virtual Connect domain, as local E/W traffic that
never travels out to the network core (Figure 3). Only a small, well-defined amount of traffic for the
connection and management protocols exits the Virtual Connect domain. The HP design:
• Optimizes the E/W traffic
• Minimizes the need for expensive switch ports
• Lets a single infrastructure administrator manage the intra-domain traffic
• Improves performance and reliability by using mostly cable-free internal chassis connections
between hosts and management services