Intelligence at the edge - wireless networking

The NBN has certainly engendered debate about fibre versus wireless. Motorola’s Roy Wittert* enters the debate and charts the future of wireless networking in Australia.

With more and more devices needing greater throughput for video and voice content, today’s wireless hub-and-spoke network architecture is showing its age. What’s needed is a wireless LAN (WLAN) architecture capable of greater intelligence at the network’s edge to optimise traffic flow without compromising security or quality of service (QoS) and driving up cost.

The innovation of the hub-and-spoke design was in routing traffic and enforcing security at the wireless controller. However, with data volumes increasing exponentially, the wireless controller is quickly becoming the bottleneck for throughput. Trying to address this bottleneck using traditional WLAN solutions ultimately means an ‘either-or’ trade-off: either a significant new investment in additional wireless controllers and wired switches or a greatly reduced QoS and user experience.

To take a step forward, what’s needed is a solution that takes full advantage of the 802.11n standard. This architecture could maximise network performance and traffic without compromising QoS for video and voice, security, mobility or survivability, while at the same time minimising both capital and operational expenditures for a lower total cost of ownership.

Distributed intelligence

Ultimately what’s required is a fundamentally different model: an architecture that provides more intelligent routing at the perimeter of the network, rather than the centralised hub-and-spoke model. This can be achieved with a more intelligent perimeter, using smart, adaptive wireless access points to offload some of the higher-level intelligence and functionality of the controller itself.

Distributed intelligence allows more of the on-site data flow to be routed internally on the edge of the network using the 11n access points, rather than sending that data to the wireless controller and back. It maintains the strength of the entire WLAN infrastructure, while increasing the ability of the ‘spokes’ to communicate directly with one another along an optimal path, even prioritising more critical data (such as VoIP and video) while providing full security and mobility services.

Not all 802.11n solutions are created equal, however. They can vary greatly in their range of capabilities. A more adaptive, reliable and intelligent architecture considers factors such as: How well do access points interact with controllers? How many controllers are needed? What are the power requirements? How does the survivability of the system compare? It leverages the network’s distributed intelligence to help unlock the full value of 802.11n solutions so they can both deliver a better quality of experience and make IT budgets go further.

By having more intelligence in the access points, during outages these access points can also serve a bridging function to reduce latencies. Since security is as important to the organisation as solid network coverage and availability, it is important to make sure that any distributed architecture has enough application awareness to be self-healing without dropping VoIP calls and that it is able to deliver the same firewall capabilities as hub-and-spoke to avoid compromising QoS.

This helps maintain network services throughout outages, ensuring the organisation and its assets continue to benefit from continued local QoS prioritisation, authentication, security policies and direct routing as well as backhaul failover to 3G.

Bang for the buck

Greater intelligence at the edge of the network can also make IT budgets go further, offering advantages in both capital and operational expenditures. Adding 802.11n access points to the network can be less expensive than adding more controllers and can actually result in significant savings since access points with greater intelligence can reduce the number of controllers needed.

Since capital expenditures are largely a function of the number of access points and controllers plus the cost of the sensors, distributed network intelligence offers certain CapEx advantages when combined with 802.11n performance. For one thing, it requires a much lower controller-to-access point ratio, with higher power access points covering a greater area.

Now with distributed traffic management, a single controller can oversee up to eight times the number of access points. This frees up controllers to focus on large-scale network and policy management as well as other services, resulting in a more efficient architecture. Access points with built-in sensors for security and troubleshooting can also eliminate extra installation and power costs that would come with a separate sensor network.

By allowing controllers to scale more, networks with distributed intelligence enable real-time troubleshooting and spectral analysis for greater survivability and reduced maintenance costs. The best distributed intelligence solutions will even factor in power consumption as a cost-saving feature, optimising the power draw of access points to fall below the 13 W maximum typical of Power-over-Ethernet solutions to avoid upgrades.

It also leverages these efficiencies for savings in operational expenditures since, without the right tools, OpEx can easily outpace CapEx within five years. To deliver OpEx advantages, network architecture must use distributed intelligence to address either the cost of repairs or the cost of downtime to an organisation.

For instance, now that access points are built smart enough to be virtual LAN (VLAN) aware, it is not necessary to re-engineer the network’s VLANs in order to add them in. Moreover, access points that distribute intelligence throughout the network greatly facilitate remote troubleshooting and advanced self-healing. Such features help deliver optimal 802.11n performance, since WLAN architecture that’s not smart enough to fix itself when problems arise drives up support costs. The only alternative is to send technicians on site for each intervention, which can be very expensive for distributed organisations.

The future of wireless network architecture relies on distributed intelligence that meets the performance demands of the new wireless world without compromising security or QoS. New architectures are available today that are natively designed to distribute intelligence and security to the edge of the network, helping IT departments provide a better quality of experience for mobile voice, video and data, gain the flexibility required to meet evolving infrastructure needs and deliver a lower total cost of ownership across the lifetime of their mobility investment.

The advantages of the centralised hub-and-spoke architecture helped bring more cost-effective 802.11b/g solutions to market but, with increased network traffic creating bottlenecks at the controller and an unreliable user experience, the industry should be looking to a more distributed model to reap the full benefits of what 802.11n has to offer.

*Roy Wittert is the Sales Manager of Motorola Solutions’ Wireless Network Solutions group in Australia and New Zealand. With more than 15 years’ experience in the IT and communications industries, Wittert has successfully grown Motorola Solutions’ footprint in Australia and established the brand as one of the leading suppliers of advanced end-to-end, indoor and outdoor wireless LAN, wireless mesh and intelligent access controller software in the country.

Motorola Solutions is an innovator and pioneer of wireless networking solutions servicing high-profile enterprise, education, healthcare and government customers in Australia