Managing convergence - the key points every company should know about

Effective converged voice and data networks aren't just about a one-off migration or kit overhaul. Doing it right takes ongoing management, says Anthony Plewes, and there are a number of things to consider...

Exactly when to adopt a converged network has been one of the main questions taxing enterprises over the last couple of years. But now that all of the major players in the enterprise communications world have embraced IP, they no longer need to worry because soon, it seems, they will have no choice.

As an investment in convergence becomes less speculative, most vendors now have significant product offerings in the packet PBX space, which uses the LAN model to deliver voice over the data network. And that's an important development, because it's what most businesses seem to want as a priority. The skill now, of course, is to manage the convergence process effectively.

Although there's a significant cost advantage to running a converged voice and data network, businesses need to be aware of the potential upfront costs that stand between their current network and one that handles converged traffic.

Frost and Sullivan published some ROI research on early IP telephony installations last year which found that some of the ROI tools suggested by the vendors were out by as much as 9 months. Deliberate or not, this was mainly because there were some additional costs that the vendors’ ROI tools did not identify. Reassuringly however, the majority of enterprises did actually receive ROI within 18 months.

It is vital that companies looking to roll out converged networks do undertake a proper network audit. In particular, voice quality problems are most likely to occur on the WAN, where the bandwidth available for transmission is less than that available on the LAN. However, problems can occur on the LAN, especially when using other bandwidth-intensive applications that can cause major problems for packet voice or video transmissions.

It is possible to avoid some of these problems by using strict policy management and most current routers come with quality of service (QoS) features that allow businesses to prioritise voice and video packets. A managed service contract should come with an SLA that encompasses a minimum QoS guarantee. This should appeal to the larger business.

In fact, for the larger concern, analyst house the Yankee Group recommends a network audit and traffic management study for all systems that will be supporting more than 35 users. This involves an assessment of all the network hardware and a topology review to identify any possible bottlenecks or problems. The traffic management study can show any potential problems with bursty applications impacting on voice performance. For example, the Yankee Group recommends that during peak hours all applications should take up between 50-75 per cent of all bandwidth available, as a rough guide.

The importance of the initial audit is reflected in the sort of services being offered to companies in the UK. Crane Telecommunications is the main distributor of the Avaya product line, and Tim Brooks, product marketing director, says that it offers a training course to its reseller partners called Five Steps to Convergence. This programme outlines the need for a two-pronged network audit, which is carried out using a pair of Avaya tools.

The first is an infrastructure testing application that determines the readiness of the network to support voice and video traffic, and the second models this traffic over the network. Brooks says that these testing processes are fairly quick and customers can expect the results within a week.

Despite the range of applications enabled by converged networks, most companies are generally driven by a desire to run voice over the data network, says Simon Boyle, business development director at systems integrator Dimension Data.

“[So] our first job is to explore the other possibilities,” he explains. “Unified messaging is quite high up on the list of applications, and call recording comes up often, especially as we do a lot of work in the City.”

Even so, getting voice right is one of the main objectives of a converged network and it's common practice for the voice call to be put over a separate virtual LAN (VLAN) for ease of management. Cisco’s products, for example, illustrate this by automatically configuring the network for voice by dropping it into a VLAN, potentially easing troubleshooting and problem isolation.

Security is an issue that needs to be dealt with at the outset, given the increased importance that the converged network gains by carrying voice. Security best practice that applies to networks will also apply to converged networks, and companies will have to protect them against external attack in much the same way. Market analyst Current Analysis warns that the vulnerability of packet PBXes to denial of service (DoS) attacks and other security issues are a continuing concern. It's pretty clear vendors will have to make significant investments in R&D or expand their partnerships to deal with this issue, as they look to be lacking at the moment.

Traffic on virtual private networks (VPNs) is commonly encrypted for transmission between sites but companies have to be aware that the QoS offered by a VPN often will not match up to the QoS support offered by the LAN switch. And this will be exacerbated if any part of the VPN uses the public internet, as it may for a remote worker.

Obviously, any audit will also need to look at the issue of QoS across a mixed network environment. “There is some interoperability,” says Dimension Data’s Boyle, “but it has to be treated with caution. You have to do a careful network audit and old networks will need an upgrade.”

Some telecoms service providers are specifically targeting voice with their VPN offerings. An example of this accommodating thinking comes from Infonet, which offers a managed global IP Voice VPN designed to carry voice, data and fax traffic and link geographically disparate PBXes. The service is designed to take the sting out of migrating to an all-IP converged network and can, claims Infonet, interface to IP PBXes or through an IP gateway to legacy PBXes.

The emergence of well-trained integrators and network managers in convergence has not kept pace with its growth in the market. Over the last couple of years the IP-PBX vendors have been hard at work getting their channel partnerships up to speed with the new demands of convergence. However, according to Frost & Sullivan, this effort has been mainly targeted at sales training rather than the technical aspects and so there continues to be a chasm between professionals proficient in data networks and those skilled in voice.

Because of this it is now common to hear experts warn companies must hang onto their own voice specialists.

And if there are not enough skills within the organisation, then it is important for companies to get adequate support from their channel partner. Some integrators even offer remote network management that will allow them to continuously support the performance of the converged network for any company. Vendors with a newfound penchant for offering professional services may be keen to help, as are the telecoms service providers. The bottom line is that with so much management help available, there's never been a better time to find good value.

If you have a view on convergence drop us a line at editorial@silicon.com. We'll be bringing you more news, analysis and opinion on this subject over the coming weeks.