Migrating to Network Virtualization
Virtualization has not only been limited to storage and server capabilities; it now includes the network. Learn about the aspects of network virtualization that you should know before implementing, some key network virtualization options for solution providers and how to take advantage of them.
Storage virtualization and server virtualization have existed for years, allowing additional workloads to run on existing devices or group and provision resources, regardless of their physical locations. However, virtualization has not only been limited to servers and storage systems but extends to the entire network and extends to end-user devices. This article discusses network virtualization ideas, key implementation considerations and opportunities for key solution providers.
Network virtualization is an abstraction process that separates the logical behavior of the network from the underlying physical resources of the network. Network virtualization enables aggregation and provisioning of networks by combining different physical networks in a single virtual network or by dividing a physical network into multiple isolated virtual networks. This is sometimes called "external network virtualization". Network virtualization can also be used in virtual servers to create synthetic networks between virtual machines (VMs). This is often called "internal network virtualization".
"VLAN technology is a good example of an external virtual network: many logical networks can run on a VLAN-enabled switch," said Scott Gorcester, president of Moose Logic, solutions provider in Bothell, Washington. Networks would be facilities built into the virtual server software, such as Microsoft Hyper-V, Citrix XenServer, and VMware products. "
Suppose the client requires a separate network for iSCSI traffic, application development, or other business purposes. Normally, this would create (and incur expenses) for another physical network requiring network virtualization, which would allow the creation and configuration of a new logical network with the same physical hardware. The new network can be isolated from other virtual networks, although it uses the same physical cable, switches, routers, and other devices. This ensures security between virtual networks. In addition, the new network could be created with some (possibly) modifications to the physical network that can be configured and managed.
This type of flexibility is not possible with physical networks. "If we are not on a physical switch, we will have to buy another one," said Carlos E. Vargas, senior analyst at Exelon Corp., an energy company in Chicago. "In the virtual world, we are only changing the size of our switch and restarting the virtual host, and we are back in business."
Network virtualization is more efficient when other forms of virtualization already exist. "Friction ensures that we have all the parts we need in the right places," said Sobel. "When server and storage components are virtualized, the idea of virtualizing switches makes more sense," he said, noting that network virtualization was a natural extension of virtual servers and storage.
In the past, network virtualization was the domain of large hosting companies that used technology to create logical environments for each of their subscribers. Medium and large businesses use network virtualization to separate networks based on their business activity or geographic location, often in conjunction with compliance requirements. Businesses also use technology to provide security between the customer and their business partners, which requires some form of access to the customer's network. Small and medium-sized enterprises (SMEs) may not yet be ideal candidates for network virtualization. However, experts such as Sobel believe that the rapid adoption of storage and server virtualization, coupled with falling prices for high-performance network hardware, can make network virtualization a technology that is appropriate for small businesses. from 2009 or 2010.
Upgrades that might be needed for network virtualization:
Although network virtualization hardware and software is available, implementation in enterprises requires careful planning. Bandwidth is the most obvious consideration. In some cases, creating multiple virtual networks is a security game that isolates existing traffic, usually to achieve specific compliance goals. However, this is rare and virtual networks are more commonly used to improve network utilization by supporting additional workloads. Virtualization itself should not add additional traffic to the network, but it must be explained by additional workloads. Some parts of the network (especially backbone) may need to be upgraded to 1 gigabit Ethernet (GbE) or even 10 gigabit Ethernet. Also consider the types of traffic in the virtual network. VLANs block broadcast traffic. As a result, applications that use broadcast traffic may not work properly. Bandwidth upgrades may require faster (and possibly wired) ports, but network switches and routers must also be validated to support virtualization. For example, the switches must run the virtualization software with other software modules. "You need to make sure your processors and storage on your switches and routers can handle the extra workload," said Michael S. Wherry, Technical Architect at Global Hyatt Corp. in Chicago. Wherry referred to a recent internal project in which all routers were evaluated and adapted to support MPLS (Multi-Label Protocol Switching) cloud traffic. Network virtualization also raises the question of redundancy. As more and more workloads are run on existing hardware, errors and failures further affect your client's performance. Solution providers who are evaluating an existing infrastructure or planning a network virtualization project should identify individual sources of error and recommend corrective actions to ensure stable operation. For example, critical servers in a cluster can be configured to share processing resources and connectivity. If an element of the cluster fails, the remaining elements assume processing to handle the flow of data. Similarly, redundant switches can be implemented using failover techniques to move traffic in the event of an error. Network virtualization increases the complexity of the customer's environment. Each new virtual network makes it difficult to return virtual resources to the underlying physical resources. Limit the number of virtual networks to minimize complexity. "If you create too many VLANs, this network infrastructure becomes a nightmare that you can manage," said Vargas. Each network virtualization project requires virtualization-aware management tools that you can use to create, configure, implement, and report on virtual networks created for your customer. Bandwidth monitoring and reporting can also be an important management function, not only to ensure trouble-free operation from a technical point of view but also to enable accurate measurement for network users (when a client uses a billing model).
Software and hardware elements of network virtualization:
Network virtualization can be implemented at the server or cluster level using the hypervisor software. You can create a virtual network in a single system. The hypervisor specifies the abstraction layer that permits different types of internal networks to mimic the physical world. Hypervisor products include VMware ESXi, Citrix XenServer 5, Virtual Iron virtual software, Microsoft Hyper-V Server 2008, and Open Source VirtualBox. If you are connecting multiple systems, the network itself must support virtualization in routers and switches. This may require the use of managed (or "smart") switches, often referred to as Layer 3 switches. The switches run virtualization software modules that synthesize the physical ports of the switch and the surrounding network into the VLANs. Fortunately, VLAN-enabled switches are readily available. "VLAN technology is now widely available, from high-level providers such as Cisco to intermediate providers such as DLink," Gorcester said. This relationship between hardware and software leads to convergence. For example, a Smart Layer 3 switch can run the VMware virtualization software. Experts point out that vendors work together to ensure interoperability that can only contribute to the adoption of virtualization. "Cisco is currently working on integrating its technology into several hypervisor network topologies," Vargas said. "This allows Cisco to extend the physical network to the virtual world."
Channel opportunities in network virtualization:
The initial deployment and deployment of a network virtualization project creates revenue opportunities. Customers work with smaller IT teams, especially when the business environment is shrinking. As a result, it is also increasingly attractive for large companies to rely on the services of an experienced solution provider. "It's not one of the things you want to sit down on and try to understand the weekend, especially if you work with compliance," Wherry said. In addition to the initial installation, solution providers can find recurring revenue opportunities in auditing and day-to-day administration. For example, the scan verifies that the client environment is always secure and that the virtualization project has not exposed the resources to unexpected threats. Experts such as Sobel point out that network virtualization projects rarely exist in isolation and are usually an extension of previous virtualization initiatives that impact storage and servers. "I think a network virtualization project does not make sense in itself," said Sobel. "Nobody would say," I want to virtualize your network "and talk only about switch virtualization. As a result, solution providers can find additional project capabilities to extend the virtual environment to other elements of the customer's infrastructure. i.e. a solution provider may reveal cost savings by suggesting a future server virtualization project to consolidate the remaining application servers into a single platform. In some cases, a solution provider recommends going back to a network virtualization project until the other elements of the client infrastructure are virtualized. Successful virtualization initiatives require planning. "The customer has to sit down with the solution provider and plan where to get their environment back in the next three to five years (...) and start working on it," Vargas said. Many solution providers choose to plan and implement phased virtualization initiatives. They often decide to start with nonessential elements of the environment. This minimizes outages and allows the customer to have greater confidence in virtualization before it is transferred to the entire company. Planning should also include a perspective on future network technologies. As more and more workloads are processed with less hardware, additional network bandwidth needs to be added. Vargas said that unified matrix technology is a short-term development that allows the coexistence of native storage and network traffic in the same network. The Cisco Nexus 7000 Series Switching Platform, which supports IP and Fiber Channel traffic over the same 10GbE cable (Fiber Channel over Ethernet or FCoE), is one example. Continued adoption of 10 GbE and subsequent development of 100 GbE should also provide additional bandwidth.