WHAT IS HYBRID CLOUD? 

A hybrid cloud is an integrated cloud service utilising both private and public clouds to perform distinct functions within the same organisation.


All cloud computing services should offer certain efficiencies to different degrees but public cloud services are likely to be more cost efficient and scalable that private clouds. With hybrid cloud, an organisation can maximise their efficiencies by employing public cloud services for all non-sensitive operations, only relying on a private cloud where they require it, with it ensuring that all platforms are seamlessly integrated.

Examples of how Hybrid Clouds can be used

Hybrid cloud models can be implemented in a number of ways:

• Separate cloud providers team up to provide both private and public services as an integrated service
• Individual cloud providers offer a complete hybrid package
• Organisations who manage their private clouds themselves sign up to a public cloud service, which they then integrate into their infrastructure

In practice, an enterprise could implement hybrid cloud hosting to host their e-commerce website within a private cloud, where it is secure and scalable, but their brochure site in a public cloud, where it is more cost effective (and security is less of a concern).

Alternatively, an Infrastructure as a Service (IaaS) offering, for example, could follow the hybrid cloud model and provide a financial business with storage for client data within a private cloud, but then allow collaboration on project planning documents in the public cloud – where they can be accessed by multiple users from a convenient location. 

Features

1. SCALABILITY
   Whilst private clouds do offer a certain level of scalability depending on their configurations (whether they are hosted internally or externally for example), public cloud services will offer scalability with fewer boundaries because resource is pulled from the larger cloud infrastructure. By moving as many non-sensitive functions as possible to the public cloud, it allows an organisation to benefit from public cloud scalability whilst reducing the demands on a private cloud
2. COST EFFICIENCIES
   Again, public clouds are likely to offer more significant economies of scale (such as centralised management), and so greater cost efficiencies, than private clouds. Hybrid clouds, therefore, allow organisations to access these savings for as many business functions as possible whilst still keeping sensitive operations secure.
3. SECURITY
   The private cloud element of the hybrid cloud model not only provides the security where it is needed for sensitive operations, but can also satisfy regulatory requirements for data handling and storage where it is applicable
4. FLEXIBILITY
   The availability of both secure resource and scalable cost effective public resource can provide organisations with more opportunities to explore different operational avenues

For example, an enterprise can deploy an on-premises private cloud to host sensitive or critical workloads, but use a third-party public cloud provider, such as Google Compute Engine, to host less-critical resources, such as test and development workloads. To hold customer-facing archival and backup data, a hybrid cloud could also use Amazon Simple Storage Service (Amazon S3). A software layer, such as Eucalyptus, can facilitate private cloud connections to public clouds, such as Amazon Web Services (AWS).

Hybrid cloud is particularly valuable for dynamic or highly changeable workloads. For example, a transactional order entry system that experiences significant demand spikes around the holiday season is a good hybrid cloud candidate. The application could run in private cloud, but use cloud bursting to access additional computing resources from a public cloud when computing demands spike. To connect private and public cloud resources, this model requires a hybrid cloud environment.

Another hybrid cloud use case is big data processing. A company, for example, could use hybrid cloud storage to retain its accumulated business, sales, test and other data, and then run analytical queries in the public cloud, which can scale to support demanding distributed computing task

Public cloud vs. private cloud and hybrid cloud

The term public cloud arose to differentiate between the standard cloud computing model and the private cloud, which is a proprietary cloud computing architecture dedicated to a single organization. Private cloud differs from public cloud, as it serves as an extension of a company's existing data center and is accessible only by that company.

A third model, the hybrid cloud, is maintained by both internal and external providers. In effect, a hybrid cloud is a combination of public and private cloud services, with orchestration between the two. In some cases, this model is attractive because it enables organizations to tap into the benefits of the public cloud, while maintaining their own private cloud for sensitive, critical or highly regulated data and applications.

Conclusion

Hybrid cloud can be an effective solution for a businesses with a tight focus on security or unique physical presence demands. Although there's seemingly less risk in a hybrid cloud model, a connection to the public cloud does have data security implications. This, however, is true of almost any public network communication.

And while the upfront cost of server hardware for the private end of the hybrid cloud is high, the control that IT departments can wield over hardware selection and system design for the private component offers an invaluable way of properly tailoring resources to the business's needs. Assembling a private cloud to handle a standard workload, with burst compute offloaded to the public cloud, can be a long-term budget-friendly arrangement.

Ultimately, hybrid cloud allows organizations to leverage public cloud pservices without offloading the entirety of their data to a third-party data center. This provides a great deal of flexibility in computing tasks, while keeping vital components within the company firewall.

WHAT IS PUBLIC CLOUD? 

The most recognisable model of cloud computing to many consumers is the public cloud model, under which cloud services are provided in a virtualised environment, constructed using pooled shared physical resources, and accessible over a public network such as the internet.

A public cloud is one based on the standard cloud computing model, in which a service provider makes resources, such as virtual machines (VMs), applications or storage, available to the general public over the internet. Public cloud services may be free or offered on a pay-per-usage model.

The main benefits of using a public cloud service are:

• it reduces the need for organizations to invest in and maintain their own on-premises IT resources;

• it enables scalability to meet workload and user demands; and

• there are fewer wasted resources because customers only pay for the resources they use.

Public cloud architecture

Public cloud is a fully virtualized environment. In addition, providers have a multi-tenant architecture that enables users -- or tenants -- to share computing resources. Each tenant's data in the public cloud, however, remains isolated from other tenants. Public cloud also relies on high-bandwidth network connectivity to rapidly transmit data.

Public cloud storage is typically redundant, using multiple data centers and careful replication of file versions. This characteristic has given it a reputation for resiliency.

Public cloud architecture can be further categorized by service model. Common service models include:

• software as a service (SaaS), in which a third-party provider hosts applications and makes them available to customers over the internet;

• platform as a service (PaaS), in which a third-party provider delivers hardware and software tools -- usually those needed for application development -- to its users as a service; and

• infrastructure as a service (IaaS), in which a third-party provider offers virtualized computing resources, such as VMs and storage, over the internet.

Public cloud pros and cons

In general, the public cloud is seen as a way for enterprises to scale IT resources on demand, without having to maintain as many infrastructure components, applications or development resources in house.
The pay-per-usage pricing structure offered by most public cloud providers is also seen by some enterprises as an attractive and more flexible financial model. For example, organizations account for their public cloud service as an operational or variable cost rather than as a capital or fixed cost. In some cases, this means organizations do not require lengthy reviews or advanced budget planning for public cloud decisions.
However, because users typically deploy public cloud services in a self-service model, some companies find it difficult to accurately track cloud service usage, and potentially end up paying for more cloud resources than they actually need. Some organizations also just prefer to directly supervise and manage their own on-premises IT resources, including servers.
In addition, because of the multi-tenant nature of public cloud, security is an ongoing concern for some enterprises evaluating the cloud. While public cloud providers offer security technologies, such as encryption and identity and access management tools, some organizations -- especially those with strict regulatory or governance requirements -- choose to keep workloads on premises.

Public cloud providers and adoption

The public cloud market is led by a few key players, including Amazon Web Services (AWS), Microsoft Azure and Google Cloud Platform. These providers deliver their services over the internet and use a fundamental pay-per-usage approach. Each provider offers a range of offerings oriented toward different workloads and enterprise needs

Examples of Public Cloud

The most salient examples of cloud computing tend to fall into the public cloud model because they are, by definition, publicly available. Examples include: 

• Cloud storage services
• Online software applications
• Cloud hosting, including website hosting
• Cloud based development environments 

To some extent they can be defined in contract to private clouds which ring-fence the pool of underlying computing resources, creating a distinct cloud platform to which only a single organisation has access. Public clouds, on the other hand, provide services to multiple clients using the same shared infrastructure. Public clouds are used extensively in offerings for private individuals who are less likely to need the level of infrastructure and security offered by private clouds. However, enterprises can still utilise public clouds to make their operations significantly more efficient, for example, with the storage of non-sensitive content, online document collaboration and webmail.

WHAT IS PRIVATE CLOUD? 

A private cloud is a particular model of cloud computing that involves a distinct and secure cloud based environment in which only the specified client can operate.

Private cloud refers to a model of cloud computing where IT services are provisioned over private IT infrastructure for the dedicated use of a single organization. A private cloud is usually managed via internal resources.

The terms private cloud and virtual private cloud (VPC) are often used interchangeably. Technically speaking, a VPC is a private cloud using a third-party cloud provider's infrastructure, while a private cloud is implemented over internal infrastructure.
Private clouds may also be referred to as enterprise clouds. 

A virtual private cloud (VPC) is an on-demand configurable pool of shared computing resources allocated within a public cloud environment, providing a certain level of isolation between the different organizations (denoted as users hereafter) using the resources. The isolation between one VPC user and all other users of the same cloud (other VPC users as well as other public cloud users) is achieved normally through allocation of a private IP subnet and a virtual communication construct (such as a VLAN or a set of encrypted communication channels) per user. In a VPC, the previously described mechanism, providing isolation within the cloud, is accompanied with a VPN function (again, allocated per VPC user) that secures, by means of authentication and encryption, the remote access of the organization to its VPC cloud resources. With the introduction of the described isolation levels, an organization using this service is in effect working on a 'virtually private' cloud (that is, as if the cloud infrastructure is not shared with other users), and hence the name VPC.

VPC is most commonly used in the context of cloud infrastructure as a service. In this context, the infrastructure provider, providing the underlying public cloud infrastructure, and the provider realizing the VPC service over this infrastructure, may be different vendors.

Techopedia explains Private Cloud

There is some controversy around the very idea of a private cloud. The central idea of cloud computing is an organization should not need to build out and manage computing infrastructure itself. By utilizing cloud vendors, an organization should lower costs while receiving services and applications that are on par or better than what could be done in-house. Given this, a private cloud would seem to be going backwards. An organization would still need to build out and manage the private cloud infrastructure and not get any benefits from the economies of scale that should come with cloud computing.

The flip side of this argument is that not all organizations can give up control to third-party vendors. A proponent of private clouds would argue there are still significant benefits to private clouds in the sense that a private cloud is a way to centralize large installations of IT infrastructure in a highly virtualized manner while avoiding exposure to the unknowns of an outside cloud vendor.

As with other cloud models, private clouds will provide computing power as a service within a virtualised environment using an underlying pool of physical computing resource. However, under the private cloud model, the cloud (the pool of resource) is only accessible by a single organisation, therefore providing that organisation with greater control and privacy.


Features and Benefits of Private Clouds:

1. HIGHER SECURITY AND PRIVACY
   While public cloud services offer a certain level of security, private clouds are the more secure option. This is achieved using distinct pools of resource with access restricted to connections made from one organisation’s firewall, dedicated leased lines and on-site internal hosting
2. MORE CONTROL
    As a private cloud is only accessible by a single organisation, that organisation will have the ability to configure and manage it inline with their needs to achieve a tailored network solution
3. COST AND ENERGY EFFICIENCY
    Implementing a private cloud model can improve the allocation of resources within an organisation by ensuring that the availability of resources to individual departments/business functions can directly and flexibly respond to their demand. They make more efficient use of the computing resource than traditional LANs and can also reduce an organisation’s carbon footprint
4. IMPROVED RELIABILITY
   Even where resources (servers, networks etc.) are hosted internally, the creation of virtualised operating environments means that the network is more resilient to individual failures across the physical infrastructure. Virtual partitions can, for example, pull their resource from the remaining unaffected servers
5. CLOUD BURSTING
   Some providers may offer the opportunity to employ cloud bursting, within a private cloud offering, in the event of spikes in demand. This service allows the provider to switch certain non-sensitive functions to a public cloud to free up more space in the private cloud for the sensitive functions that require it 

Private Cloud Characteristics

Private cloud services can vary considerably and so it is hard to define what constitutes a private cloud from a technical aspect. Instead such services are usually categorised by the features that they offer to their client. Traits that characterise private clouds include:

• Ring fencing of a cloud which has multiple clients accessing virtualised services, which all draw their resource from a distinct pool of physical computing. These may be hosted internally or externally and may be accessed across private leased lines or secure encrypted connections via public networks
• Additional security, which is ideal for enterprises that need to store and process private data or carry out sensitive tasks. For example, a private cloud service could be utilised by a financial company that is required to store sensitive data internally and who will still want to benefit from some of the advantages of cloud computing, such as on-demand resource allocation

Have you ever watched this typical B-grade summer blockbuster flick or neverending CSI-like detective series where they show you a really skillful hacker "breaking" through the mainframe?

Well, apparently, there is no such thing and the mainframe would not succumb to hacker attacks.
Linus clears out this situation for us in the new Techquickie video:

Top Operational Challenges of Network Virtualization

The trend of virtualization is one of the most powerful forces in technology. Using data abstraction and control, the functions of compute, networking, and storage are being virtualized to create a more flexible software platform for delivering digital workloads and services to customers.

The vision is that, eventually, nearly all digital and computing services will be controlled by open and compatible software interfaces, automating the orchestration of resources behind the scenes – often from the cloud. Ordering up and controlling services ranging from cloud computing to virtual private networks will be as easy as pushing the buttons on your TV remote.

This virtualized infrastructure is bringing enormous benefits to the technology world, but nobody said it was easy. This massive, worldwide migration of control from the physical to the virtual is a complicated process. Decades of procurement, administration, and business processes are being changed.

The No. 1 focus of IT management is virtualization. In Protiviti’s “2015 IT Priorities Survey,” 86% of those surveyed labeled it a “significant priority.” This survey had more than 1,000 respondents including CIOs, IT vice presidents, and IT directors. The second highest priorities were security related, with 83% citing virus and advanced threat eradication as a significant priority; data breach and privacy laws also came in at 83%.

All of these issues are connected, of course. Security and virtualization go hand-and-hand in the cloud (see “Why Security Is a Leading Network Virtualization Driver”). In the legacy, physical world of computing, resources could be cordoned off by physical or software firewalls. But as the world’s computing power is migrated to the cloud and connected to the Internet, security must become more virtual as well.

Computing power has been transformed by server virtualization and the cloud model. The next step is to extend that to network virtualization (NV). In our recent “2015 Special Report: Network Virtualization in the Data Center,” our research and user survey generated a lot of information about the operational challenges of NV. Below are the some of top operational challenges that IT managers should watch out for in their shift to NV.

Scalability

When asked to identify the top two attributes organizations are looking for from NV solutions, scalability got a majority vote in our research – from 51% of those polled. Some NV solution may have performance challenges when the control planes reach their limits or when the data plane replicates broadcast, unknown unicast, or multicast traffic across the physical fabric. Vendors are working to overcome these limitations, but whether the solutions can scale to support large cloud environments with tens of thousands of physical servers is yet to be seen.

Openness of Solution

In our survey of the top two attributes of NV, openness and interoperability came in second at 39%, which speaks to the heterogeneous nature of most organizations and their need to ensure the solutions work together.

Look for NV solutions that support standard protocols to improve compatibility with other network elements. VXLANis the most popular encapsulation protocol today. On the direct-fabric programming side of the equation, the OpenFlow protocol is the most prevalent southbound protocol supported by switches, enabling the NV solution to have a wider reach. Cisco’s proprietary ACI has also experienced strong market adoption.

Usability and Manageability

Ease of implementation and performance came in at 36% and 35%, respectively, in our survey of most important attributes. Usability and manageability are key considerations. The control and management panels for these solutions have to accommodate tens of thousands or hundreds of thousands of networks (perhaps millions in the near future). This unprecedented scaling presents a new challenge for user interfaces.

Hypervisor Compatibility

Another version of openness: Virtualization customers need to make careful distinctions among the many hypervisor solutions out there and determine whether they work together. Some solutions are marked “compatible” with the hypervisor, but they might be using a virtual switch instance running in a virtual machine (VM). This is true with VMware’s ESXi, which today restricts choices of virtual switches to its built-in version or limited partners. These issues are being solved with more workarounds, however, and non-VMware vendors are beginning to improve VM performance issues.

Network Model

Choosing the network model can have huge architectural implications. Look for a mature NV solution that provides a network model that helps visualize and define the topology – including Layer 2, Layer 3, routing, gateways, Layer 4-7 chaining, and so on. The more complex the environment, the more critical the model is to ensuring it is working properly.

Physical Switch Compatibility

NV solutions try to operate primarily within the virtual domain, but most still require some integration with the physical infrastructure. The availability and performance of physical-to-virtual gateways is critical. For NV solutions using VXLAN, there is an increasing number of switches that can act as hardware VTEPs (VXLAN termination endpoints) to facilitate these boundary transitions at wire-speed.

High Availability

Many networks are jitter- or latency-sensitive, such as those supporting streaming media, voice, or critical apps (e.g., financial and medical), where the presence of QoS support (Layer 2/Layer 3) can be helpful. In such environments, NV solutions based on direct-fabric programming may be able to provide better QoS control than pure overlay solutions.

Visibility and Analytics

Visibility is critical for network troubleshooting and management. The ability to look into overlay tunnels and understand how they traverse a particular physical path is key to optimizing the network’s performance.

NV vendors tout monitoring and analysis within their solutions, with the ability to analyze traffic trends (throughput, latency) within the solution itself. However, most of these implementations are relatively basic, focusing on data capture. Look for capabilities to mature in the coming months to improve analysis.

These are the most critical issues we found when examining the operational approach to NV.

Network virtualization explained

Server virtualization and storage virtualization have been around for years, allowing additional workloads to operate on existing devices, or pooling and provisioning resources without regard for their physical locations. But virtualization has moved beyond servers and storage systems, extending across the network and reaching all the way to user endpoints. This article explains the ideas behind network virtualization, highlights the main deployment considerations, and notes the major opportunities for solution providers.

What is network virtualization and why is it important to the channel?

Network virtualization is a process of abstraction which separates logical network behavior from the underlying physical network resources. Network virtualization allows network aggregation and provisioning, combining different physical networks into a single virtual network, or breaking a physical network into multiple virtual networks that are isolated from each other. This is sometimes called "external network virtualization." Network virtualization can also be applied within virtual servers to create synthetic networks between virtual machines (VMs); this is often dubbed "internal network virtualization."

"A good example of an external virtual network would be VLAN technology, where many logical networks can be operated on one VLAN-capable switch," said Scott Gorcester, president of Moose Logic, a solution provider located in Bothell, Wash. "Internal virtual networks would be the facilities built into virtual server host software such as Microsoft Hyper-V, Citrix XenServer and VMware products."

Network virtualization lends itself to cost savings, efficiency, security and flexibility -- four key benefits for any client. "The whole point of everything we're doing with virtualization is to get more utilization out of hardware," said Dave Sobel, CEO of Evolve Technologies, a solution provider headquartered in Fairfax, Va. In physical environments, adding switch ports requires cabling, connections and configuration -- along with the investment in physical switch ports. In a virtual environment, logical switch ports are created and abstracted from the underlying physical ports. This allows more "virtual" switch ports to be added and "connected" (or directed) to other logical switch ports quickly and without having to commit real ports or cable them together in the data center.

Suppose that the client required a separate network for iSCSI traffic, application development or some other business purpose. Traditionally this would require the creation (and expense) of a different physical network, but network virtualization would allow a new logical network to be created and configured using the same physical hardware. The new network could be isolated from other virtual networks even though it's using the same physical cables, switches, routers and other devices. This ensures security between virtual networks. Further, the new network could be created, configured and managed with few (if any) changes to the physical network.

This kind of flexibility is impossible with physical networks. "When we are out of ports in a physical switch we need to buy another one," said Carlos E. Vargas, lead analyst at Exelon Corp., an energy company in Chicago. "In the virtual world we just change the size of our switch and reboot the virtual host and we are back in business."

Network virtualization is most effective with other forms of virtualization already in place. "The rub is making sure that we've got all the parts that we need in all the right places," Sobel said. "As you start to virtualize server and storage components, the idea of virtualizing the switches … starts to make more sense," he said, noting that network virtualization is a natural extension to virtual servers and storage.

Early on, network virtualization was the domain of large hosting companies that used the technology to create logical environments for each of their subscribers. Medium-sized to large enterprises are adopting network virtualization to separate networks by business function or geographic location -- often related to compliance obligations. Businesses are also adopting the technology to ensure security between the client and their business partners that require some form of access to the client's network. Small and medium-sized businesses (SMBs) may not be ideal candidates for network virtualization yet. But experts like Sobel predict that rapid adoption of storage and server virtualization, combined with falling prices for powerful networking hardware, may make network virtualization a suitable technology for the SMB by late 2009 or 2010.

What are the hardware and software elements of network virtualization?

Network virtualization can be implemented at the server or cluster level using hypervisor software -- you can create a virtual network on a single system. The hypervisor provides the abstraction layer that allows different types of internal networks to mimic the physical world. Hypervisor products include VMware ESXi, Citrix XenServer 5, Virtual Iron from Virtual Iron Software, Microsoft Hyper-V Server 2008 and the open source VirtualBox.

As you connect multiple systems, the network itself must support virtualization in the routers and switches. This may require the use of managed (or "intelligent") switches -- often termed Layer 3 switches. The switches run virtualization software modules that abstract the physical switch ports and surrounding network into VLANs. Fortunately, VLAN-capable switches are readily available. "VLAN technology is everywhere today, from high-end providers such as Cisco to lower-end/mid-tier vendors such as DLink," Gorcester said.

This relationship between hardware and software is leading to convergence. For example, a Layer 3 intelligent switch may be able to run virtualization software from VMware. Experts point out that vendors are working together to ensure interoperability, which can only help the adoption of virtualization. "Currently, Cisco is working to embed their technology in several hypervisor network topologies," Vargas said. "This will allow Cisco to extend the physical network to the virtual world."

What planning or upgrades may be needed for network virtualization?

While the hardware and software for network virtualization is readily available, its deployment in the enterprise requires careful planning. Bandwidth is the most obvious consideration. In some cases, the creation of multiple virtual networks is strictly a security play to isolate existing traffic -- usually to meet some compliance-related goal. This is rare, however, and virtual networks are more commonly deployed to improve utilization of the network by supporting additional workloads. Virtualization itself should add no additional traffic to the network, but the traffic from additional workloads has to be considered. Parts of the network (especially the network backbone) may need to be upgraded to 1 Gigabit Ethernet (GbE) or even 10 Gigabit Ethernet. Also consider the traffic types on the virtual network. VLANs block broadcast traffic, so applications that rely on broadcast traffic may not work properly.

Bandwidth upgrades may necessitate faster ports (and maybe cabling), but the network switches and routers will also have to be validated for proper virtualization support. For example, the switches will need to run virtualization software along with other software modules. "You have to make sure that your processors and memory on your switches and routers are able to handle the extra workload that will be placed on them," said Michael S. Wherry, technical architect with Global Hyatt Corp. in Chicago. As an example, Wherry pointed to a recent in-house effort where all routers were evaluated and upgraded as needed to support MPLS (Multi Protocol Label Switching) cloud traffic.

Network virtualization also raises the question of redundancy. As more workloads operate on existing hardware, faults and failures will have a greater impact on your client's operation. Solution providers that are assessing an existing infrastructure or planning a network virtualization project should identify single points of failure and recommend corrective action to ensure robust operation. For example, critical servers may be configured into a cluster to share processing resources and connectivity. When one element of the cluster fails, the remaining elements take over the processing to keep data flowing. Similarly, redundant switches may be introduced using failover techniques to shift traffic when faults occur.

Network virtualization adds complexity to the client's environment. Each new virtual network makes it more difficult to relate virtual resources back to the underlying physical resources, so limit the number of virtual networks to keep complexity to a minimum. "If you create too many VLANs, that network infrastructure will become a nightmare to administer," Vargas said. Any network virtualization project will require virtualization-aware management tools that can create, configure, provision and report on the virtual networks created for your client. Bandwidth monitoring and reporting may also be an important management feature -- not just to ensure smooth operation from a technical standpoint, but also to facilitate accurate chargeback billing to network users (if the client uses a chargeback model).

What are the channel opportunities and trends in network virtualization?

There are revenue opportunities in the initial deployment and setup of a network virtualization project. Clients are running with smaller IT teams -- especially in tightening economic conditions -- so relying on the services of an experienced solution provider is increasingly appealing, even for larger enterprises. "This is not one of those things you want to sit down and try to figure out yourself on the weekend, especially when you're working with compliance," Wherry said.

Beyond the initial installation, solution providers can find recurring revenue opportunities in auditing and regular management. For example, auditing can help verify that the client's environment is still safe and secure, ensuring that the virtualization project has not exposed any resources to unexpected threats.

Experts like Sobel note that network virtualization projects rarely exist in a vacuum, and are most often an extension of previous virtualization initiativesinvolving storage and servers. "I think a network virtualization project doesn't make much sense in its own," Sobel said. "No one would come in and say, 'I want to virtualize your network,' and talk just about virtualizing switches."

Consequently, solution providers can find additional project opportunities extending the virtual environment to other elements of the client's infrastructure. For example, a solution provider may be able to demonstrate a cost savings by proposing a subsequent server virtualization project to consolidate several remaining application servers onto a single platform. In some cases, a solution provider may recommend the reverse -- forestalling a network virtualization project until more elements of the client's infrastructure are virtualized.

Successful virtualization initiatives take planning. "The customer needs to sit down with the solution provider and plan where they want to take their environment in the next three to five years … and start working toward it," Vargas said. Many solution providers choose to plan and implement virtualization initiatives in phases -- often opting to start with nonessential elements of the environment. This minimizes disruption, allowing the client to gain confidence and see value in virtualization before it rolls out to the entire enterprise.

Planning should also involve a perspective on the future network technologies. As more workloads are handled by less hardware, additional network bandwidth must be added. Vargas pointed to unified fabric technology as one near-term development, allowing native storage and network traffic to coexist on the same network. An example of this is Cisco's Nexus 7000 series switching platform, which supports IP and Fibre Channel traffic on the same 10 GbE cable (dubbed Fibre Channel over Ethernet or FCoE). Additional bandwidth should also be available with the continued adoption of 10 GbE and the eventual development of 100 GbE.