The magic of mobility: Equipping today`s mobile worker

There is no doubt that the benefits of data mobility have been felt throughout the commercial and industrial worlds. Initially reserved for laptop-equipped senior executives, the concept of voice and data mobility - whether it is within the corporate perimeters or beyond - is now within reach of the entire workforce.

Graham Vorster, chief technology officer at Duxbury Networking, looks at the challenges faced by network designers and administrators in the mobile era.

Undoubtedly wireless technology has significantly changed the way people and enterprises communicate and conduct business. It has given executives and workers alike the mobility and freedom to work anywhere, anytime and in any manner.

Nevertheless, for many IT managers, mobile computing is still a brave new world. While mobile voice technologies have become all-but-ubiquitous, the deployment of mobile data solutions is only now gaining acceptance.

The key challenge is that while wired communication systems consist of only two components - the cable and the enabling network - wireless data systems are far more complex, encompassing the target devices, wireless networks plus data and content itself.

Then there is the mobile technology to consider. Where to start?

Companies should first look at their internal business process and keep in mind that their key objective is to extend their business processes within a secure environment.

One of the options to achieve this is through the implementation of a wireless LAN (WLAN).

US-based research authority InfoTech Primary Market Research believes that increasing comfort levels of users with WLAN technology will allow WLANs to evolve as the most robust, secure and convenient option for worker mobility.

However, a WLAN`s apparent simplicity masks an array of issues that are critical to its success as a business-based infrastructure.

As easy as it is to get a wireless network up and running, doing it correctly takes as much upfront planning and perhaps more ongoing diligence than a traditional wired network.

One thing often overlooked is that wireless LANs require wiring: wired Ethernet jacks may have to be installed in order for access points to be attached to the wired LAN.

And electrical power outlets may be needed for the access points, though some vendors offer the option of powering the access devices over Category 5 cable.

The actual WLAN design - including how many access points are placed - hinges on several factors: the type of materials used in building construction and furnishings, the number of users in a given area and whether that number changes, and the throughput those users need.

The larger the deployment and the more demanding the applications, the more complicated the equation becomes.

Be on the look out for a mistake often made at this time: using one brand of interface card and access point for the initial design, then a different brand in the final deployment.

Doing so can lead to surprises stemming from different radio frequency propagation characteristics, which leads to dead spots and lower bandwidth.

One of the most confusing design issues centres on WLAN standards.

The11Mbps 802.11b standard access points have a maximum of three non-overlapping channels for users. Too many access points, haphazardly placed, will overlap these channels and users will see a serious drop in performance because of contention for the channel.

Proper channel configuration can allow three access points to be stacked on top of one another, giving users maximum available bandwidth.

It is wise to consider security early because WLANs are, by definition, insecure: Data is broadcast through the air and is hard to contain. The original encryption scheme for the 802.11 standard, the wireless encryption protocol (WEP), had several inherent weaknesses.

Depending on the requirements, security can range from turning on the basic WEP encryption to full-blown authentication and encryption via virtual private networks (VPNs) tied into RADIUS servers.

Perhaps it is best to treat a WLAN as if it were a public Internet, putting a firewall between the LAN and the wired net, and using a campus VPN and authentication method tied into a policy-based security environment.

A related but obscure issue is that many wireless laptop users don`t realise their wireless cards remain active, even if they`re not using the VPN.

It is possible for an attacker to use this active link to jump a worker`s laptop and infect it with a virus or other malicious code, which is transmitted to the corporate network via the VPN when the worker logs on.

For most organisations, basic security which includes at least 128-bit WEP encryption, the use of obscure network names, a clear prohibition on hooking up unauthorised access points, will not be enough.

There seems little doubt that we face convergence of not only voice and data, but also of wired and wireless networks and the standards at their core.

There are so many client devices emerging that overlap in functionality - such as wired voice-over-IP handsets, softphones, wireless 802.11 VOIP phones, desktop TDM phones, and PDAs with communications capabilities.

In addition, users who have cell phones might want to be connected to the corporate IP PBX system in some way.

In large organisations, it will pay to have a plan in place for matching the appropriate wireless devices to various user populations, as each will have different needs.

Ultimately, companies will also need to integrate communications devices and features across wired and WLAN and WAN devices and lay down a solid foundation for the convergence of these technologies within the enterprise.