Effects of virtualization and cloud computing on data center networks

This paper won’t answer all your questions about the future of data center networks, but it will identify

some industry trends and present some possible solutions. We suggest that you consider adopting

technologies that

• Reduce network hierarchy

• Optimize E/W traffic flows

• Simplify operations at the server-network edge with intelligent management capabilities that align

with the needs of all operational groups in the data center

Changing business applications

The growth of server virtualization (virtual machines or VMs), virtualized desktop infrastructures, cloud-

computing models, federated or distributed applications, and mobile access devices are all causing

shifts in networking traffic patterns toward more E/W traffic flow (Table 1). Industry sources attribute

up to 80 percent of network traffic for these next generation applications coming from E/W traffic

flows.

We expect web applications to deliver integrated, context-specific information and services. And, we

expect it right now—low-latency, high performance connections are critical. At the same time, cloud

computing and service-oriented applications are introducing more stringent service-level and security

demands.

Table 1: New software applications are driving changes to networking infrastructure.

Yesterday’s applications Applications for 2011 and beyond

Single application on single-purpose

server

Multiple applications operating on VMs within a single physical

server.

Client-server architecture Distributed computing applications (massively parallel compute

clusters)

Clusters of multiple servers in compute resource pools, requiring

server mobility within a cluster and requiring resources across

clusters.

Static deployment model Cloud computing and new service delivery models

Platform as a service (PaaS)

Software as a service (SaaS)

Infrastructure as a service (IaaS)

Storage as a service (STaaS)

“X” as a service (XaaS)

Server virtualization

Since the introduction of hypervisors over a decade ago, the increase in VM density (fostered by ever

more powerful CPU and memory subsystems) and the significant increase in VM mobility have

resulted in greater performance demands on the network subsystems at the server-network edge.

Table 2 outlines how these trends are causing traffic flow patterns to shift.