datacenter people inspecting switches

Introduction

Virtualization is a central theme in IT development and new technology implementation because it has the power to maximize IT investment. The ability to leverage the performance of critical IT infrastructure and support converged networks is proving to be an extremely high-value proposition for businesses in all industries.

The convergence of services on the network requires higher availability for mission-critical applications. Those providing advanced services to customers are well aware of the need to balance maximizing operational efficiency with meeting Service Level Agreements (SLAs).

Virtualization provides the means to meet these increasing demands, with the unique ability to also provide businesses with cost benefits such as:

  • Streamlining operational efficiency
  • Greater flexibility to adapt to changing business needs
  • Maximizing benefits from IT investment
  • Simplifying management of IT systems
  • Reducing energy consumption
  • Improving network uptime
  • Simplifying the integration of new hardware
  • Simplifying the upgrading of software applications
  • Automating the movement of data storage locations
  • Optimizing disaster recovery provisioning

Virtualization, an innovative solution for multiplying the effectiveness and value of network infrastructure, has captured the imagination and endeavour of the networking industry.

While early advances in IT virtualization relate mainly to Server and workstation technology, there are some important virtualization developments occurring in the underlying Ethernet infrastructure:

Virtualized Dual Backbone

Replacing the traditional LAN redundancy solution (a redundant pair of separate switches) with a resiliency solution based on a pair of switches operating as a single virtual switch.

Network Service Virtualization

Enabling network services, particularly security services, to be delivered in a distributed fashion across the network, without the requirement to deploy multiple specialized appliances for each service.

Virtualized Networks

Enabling multiple networks to share the same Ethernet infrastructure, but remain quite isolated from each other. This is particularly powerful when delivered in an identity-based fashion.

Allied Telesis has been delivering innovation in these areas of virtualization for some time.

Allied Telesis Switches & IT Virtualization

Integration of Allied Telesis switches with server and workstation virtualization

The Allied Telesis Enterprise LAN offering is highly compatible with successful IT virtualization, as the Allied Telesis hardware and feature set offering has been developed to deliver similar outcomes.

Waste reduction, cost optimization, and maximization of network performance and uptime have been key drivers of Allied Telesis technology development for some time, and are among the defining characteristics of the xSeries switches and the AlliedWare Plus operating system.

The flexible and expandable nature of the product line, with its low investment entry point and ability to add building blocks almost seamlessly, fits very well with the aims of IT virtualization.

The delivery of a full enterprise switching feature-set on a series of products with increasing performance and physical-resiliency capabilities enables an enterprise to target its investments at levels that are appropriate to the needs of different parts of its organization.

To fully understand the extent to which the Allied Telesis enterprise switch offering is compatible with IT virtualization, we need to look at some of the specific capabilities of the IT virtualization solutions currently available in the market.

Appropriate provisioning of hardware capacity

Server virtualization enables the network to maximize the utilization of the processing capability across all available servers. This avoids the need to over invest in individual high-powered servers which must, alone, meet the peak requirements of particular applications, but spend much of their time under utilized. Instead, that peak load can be spread across existing lower-powered units. As processing requirements increase, the capacity can be increased in a cost-effective manner by gradually adding more units. Similarly, it is possible to have a regular program whereby sets of older units are retired (or redeployed to other tasks) and replaced by a smaller number of more modern units.

This ability to provision processing capacity in a gradual and managed fashion is greatly preferable to increasing capacity in large expensive chunks, made more expensive by the need to over-provision in order to cover (unquantifiable) future growth.

Similarly, Allied Telesis has taken the approach of delivering LAN switching capacity in a manner that allows for gradual increments. With a very affordable entry cost for standalone Gigabit switches, further Gigabit, 10 Gigabit, 40 Gigabit and 100 Gigabit switching capacity can be gradually added by integrating new units into virtual chassis stacks. As older models are retired from core switching roles, they can continue to be used in access or edge roles. At no point do you need to make a big investment into a single large chassis-type switching unit that has no migration path when its useful life in the core is over.

Moreover, building core switching capacity from discrete units provides flexibility as business needs change. Individual units of switching capacity can be moved to where they are needed, rather than having to remain concentrated in a monolithic core.

Seamless addition/replacement of hardware components

Virtualization has had a remarkable affect on the ease with which physical servers can be added, removed, or replaced in the network. The ability to shift load off a particular server prior to its removal, coupled with the automatic assimilation of newly added servers, has moved the industry towards the concept of a plug-and-play data-centre. Hardware can be rearranged with zero downtime, and very little management overhead.

Similarly, the Allied Telesis product line delivers hitless hardware rearrangement:

  • Service modules can be hotswapped in and out allowing you to add extra connectivity or backbone bandwidth with zero downtime. Connectivity and bandwidth can also be rearranged within the network with zero downtime.
  • Individual switches can be swapped in and out of a virtual chassis stack with zero downtime. Just as server processing capacity can be increased in a gradual, managed fashion, so too can core switching capacity; and without the need to schedule network downtime.
  • Redundant power supplies can be hot-swapped, avoiding downtime due to power supply failures.

Reliable management of network resources

The advantages of virtualization are most fully realized when the management system is able to achieve finely tuned dynamic load balancing across different machines. This requires that the management system can closely monitor the operation of every machine, and that machines can quickly and accurately transfer processing to each other. These activities cannot be reliable unless the communications that control them are reliable.

Reliable transport of communication sessions across an Ethernet network is achieved by priority queuing within the switches. However, the increasing convergence of real-time services on the LAN creates competition for those high priority queues. VoIP, video, process control, remote desktop sessions, and Layer 2 and 3 control protocols are all sensitive to loss and delay. Adding virtualization control traffic to this mix further complicates the QoS requirements. Ensuring reliable transport of all this loss and delay sensitive data, in even the busiest circumstances, requires a sophisticated QoS implementation. Allied Telesis advanced Enterprise switches have an unparallel QoS capability. The fine-grained data classification, flexible marking, accurate shaping, and rich queuing and scheduling functionality enable the creation of QoS policies capable of meeting the most demanding requirements.

Simple, reliable disaster recovery provisioning

An emerging benefit of IT virtualization is its ability to simplify the managing of a remote site for disaster recovery.

Once the tools had been developed which enable fine-grained control of virtual machines, and data storage, within a live site, it was a small step to then include a system replication capability. So, virtual IT management systems can automate the maintenance of replicated data storage and machine images at a remote site.

A component of the effectiveness of the disaster recovery system is the provisioning of alternative data paths between the live site and the remote disaster recovery sites. The Allied Telesis solution for resilient data communication between physically separated sites is Ethernet Protection Switching Ring (EPSR), as seen in figure 5. EPSR provides carrier-grade resiliency over a ring topology. Using a simple and highly reliable loop protection protocol, it can restore communication within as little as 50ms after a link or node failure. Furthermore, it can operate over aggregated links, to provide even stronger link and path resiliency.

Using EPSR over one or more 10 Gigabit links is a cost-effective means to enable extremely reliable and rapid communications between a live site and a disaster recovery site.