The essence of convergence

What are the essential elements of a converged network? Ross Bentley presents an overview of what such a network will likely...

What are the essential elements of a converged network? Ross Bentley presents an overview of what such a network will likely comprise and why you should begin to base your business around one

Although it's been around since the early 1990s, only recently have people been using the 'c' word on a regular basis. It seems the strategy of converging voice and data networks within organisations is, today, a no-brainer, with analysts predicting that most sizeable companies in Europe will steadily migrate towards convergence over the next five years.

Golden objectives

Historically, organisations have had at least two networks. One was part of the IT infrastructure, carrying data traffic from servers in the data centre to PCs and other devices. The other was the telecommunications network used to transport voice traffic via the exchange or switch to the phone, which typically sat next to the worker's PC on the desk.

Today, an increasing number of companies are moving towards a converged network by bringing together these two separate systems for voice and data (and therefore video) on to one network, both within a main site and between sites.

Driving this trend is internet protocol (IP), a technology that is firmly established as the dominant mechanism for voice and data traffic. Earlier this year, analyst Gartner predicted 90% of all new corporate telephone systems will be IP-enabled by 2008. Already 70% of BT switch sales consist of convergent switches.

According to Don Proctor, vice-president and general manager of the Voice Technology Group at Cisco Systems, businesses are embracing convergence in pursuit of the two golden objectives that head up virtually every IT project's list of desirable outcomes: cost reduction and revenue growth.

Less hardware; centralised admin

Perhaps the most basic benefit of convergence is cost. With a converged network there is only one set of hardware, network links and security to implement and manage. This helps cut the cost of set-up, support and network bandwidth between sites.

With only one network to manage, maintenance becomes simpler and cheaper. Whereas traditionally IT has been a distinct discipline from telecoms, in the converged world voice becomes simply another application and the phone just another client, like the laptop. Administration of the networks becomes centralised in the IT department and expensive charges from telecoms services firms are drastically reduced.

Cheaper calls with IP

You can have a converged network without moving your voice to IP, but doing this brings further benefits, not least in terms of cheaper calls. The most basic approach is voice over IP (VoIP), which simply means encoding voice and sending it as IP packets.

VoIP is often used to refer to voice over the internet. With the widespread adoption of broadband this can allow businesses to benefit from cheaper calls. But the internet is a best-endeavours medium and can't guarantee business-class voice quality. To achieve this, two more concepts are required.

The local area network (Lan) can be upgraded to categorise IP packets and then prioritise voice to avoid the delays that could otherwise result in unacceptable speech quality. This is called Quality of Service (QoS)-enabling the Lan.

The same can be done for the wide area network (Wan) or VPN to enable high-quality calls between sites, without the cost of the public switched telephone network (PSTN). The only cost is the leasing of the VPN infrastructure, which may already have been provided. Finally, an IP telephony switch is used to provide these benefits along with all the functionality of a traditional PBX.

And although the IP handsets required to make and receive IP telephony calls are more expensive than traditional phones, your savings in the long term can be substantial.

Siemens calculates the average business can reduce its annual phone bill by 31% through IP trunking, while a report from telecoms consultancy Analsys in October 2004 estimated telcos in Europe could collectively lose out on £4.5bn in revenues from phone call charges over the next four years as companies like yours and consumers alike use the internet and IP telephony to make phone calls.

Further benefits of IPT

Home working and hotdesking are made easier using IP telephony. In an office where IP telephony is used, your workers are no longer tied to their desk and the extension number particular to that fixed terminal.

With intelligence built into IP handsets, the network picks up the handset's IP address wherever it is plugged in around the building, the pre-programmed privileges are quickly configured and the worker maintains his or her extension number.

And because the phones are IP devices, linked over an IP network to applications that are running on IP servers, any application can be integrated far more deeply and at significantly lower costs, due to open protocols and APIs, than was possible in the days of separate phone systems and data networks.

Connecting via a VPN to the corporate network means your home workers need only soft phone software loaded on their laptop and a headset connected to their laptop before they are automatically able to direct voice calls through a corporate network.

With customer information from a central database appearing on the laptop screen and being accessed at the same time a voice call to that customer is made, some of the potential plus points of merging voice and data in terms of customer service and productivity start to become apparent.

Two other common examples of first generation applications based on converged networks and IP telephony are unified messaging where users have one in-box for email, voicemail and video-clips, and conferencing where users can speak and work on a shared file all on the same network.

A converged network has a number of typical components. Structured cabling enables both voice and data to be carried over a single network. For IP telephony the Lan needs to be QoS-enabled so that it offers available bandwidth to voice traffic in preference to other types of data. If using IP Telephony over a Wan then the same prioritisation of voice packets is required. Across the Wan this is sometimes referred to as Class of Service (CoS).

Critical and sensitive

"Voice is more critical and sensitive than other kinds of data," says Dave Millet, regional business development manager at Avaya. "No one minds if an email takes a minute or so to arrive, but if there is even a second delay in voice transmission then users will not accept the service."

You should heed analyst firm Forrester's headline advice for companies pursuing convergence and IP telephony: 'Audit your network'. You need to know where potential bottlenecks are on your network, understand how digitalised voice data will affect the network and prepare your network to ensure adequate bandwidth is set aside for voice traffic to travel without a glitch.

"If the phone crashes as much as a PC does, you can imagine the frustration among employees," warns Millet.

Structured cable capable of carrying voice and data and connecting with an IP or hybrid switch is also an essential element of any converged infrastructure, while to make and receive calls using IPT, IP handsets are also needed.

If you are considering the move to convergence, you must ensure you have an appropriate switch or PBX installed that supports IP. Traditional time division multiplexing (TDM) switches, which have been available for the past 20 years or so, are not appropriate for use in a converged network as they do not support IP telephony.

All the signs are that the TDM switch's days are numbered. Although still available, the technology is selling in decreasing numbers and manufacturers are investing less and less in the necessary R&D. TDM is fated to eventually become a peripheral technology.

MZA, a consultancy specialising in convergence, says the market for traditional switches fell by 20% in the first half of 2004 year-on-year. It says traditional systems now account for a 51% share of the market, compared with 63% in the first half of 2003.

In many cases, you can create a converged network using elements of an existing TDM infrastructure with the introduction of a convergent switch to bring all the aspects together, and even allow sites to re-use their analogue phones. Even if you are still unsure about internet calling or wanting to migrate in stages, you can upgrade your phone systems.

Full functionality

Andy Clemens, marketing manager at BT Business, says convergent or hybrid switches are the appropriate choice for the substantial middle ground of businesses. They are designed to offer the full functionality of TDM switches, but have the architecture to support IP-based telephony when organisations are ready.

You may well wish only to converge networks at one site or may be considering the introduction of IP telephony longer term, says Clemens. In such a situation, a hybrid switch ensures that investments in switch upgrades are future-proofed.

"There is price parity between TDM switches and IP-enabled switches, so if you have to upgrade your switches why wouldn't you go hybrid?" says Clemens.

However, Mike Valiant, 3Com's international market development manager for enterprise voice solutions, feels that "belting on" IP-enabled switches to an existing platform has its limitations for companies wanting to exploit the new business processes IP telephony makes possible. "As you move towards full IP telephony, you may struggle with some applications and scalability. Ultimately, you will have to upgrade - hybrid systems do have their limitations," he says.

If you are ready to implement a full IP telephony network across your business, IP telephony switches are optimised to carry digitalised voice and data and support IP applications. Many of the firms that have so far committed to a full-blown IPT have done so as part of a move to a green site, where they have had to install a switch from scratch, although as older hybrid switches are replaced as they come to the end of their useful life, analysts expect to see more IPT switches installed.

John Brogan, group IT manager at Four Seasons, a company that manages over 350 nursing homes in the UK, went with the decision to install an IPT switch after his company announced it was opening a new accounting office in Darlington.

"We had an opportunity to put in a new platform, but at the moment only three sites use IP telephony and we haven't made use of any of the applications. We have only touched on what a fully converged system can do but we put in an IP switch now rather than having to revisit our needs two years down the line and needing to update then," he says.

As more firms adopt converged networks, analyst predict we shall see an increasing number of applications that make use of this close association between voice and data. "As IP reaches critical mass, more applications will be written for it," predicts Avaya's Millett.

Prototype application

But already we are seeing clever uses of IPT. Millet talks about a prototype application, developed for professionals, such as lawyers, for whom time is money, that times how long a telephone call lasts before automatically creating a bill and e-mailing it to the client.

Valiant at 3Com points to an estate agency business in the US that employs 750 agents and has developed an application combining messaging technology with IPT. A customer who sees a property they would like to view on the website enters their details.

A text-to-voice engine kicks out the message to the agent nearest the property, and leaves a voicemail for that agent. Accessing the message, the agent is able to call the customer back within the hour, enabling impressive level of service and thus competitive advantage.

Closer to home, Peter Wignall, head of infrastructure marketing at BT Business, recalls a software engineer who noticed employees working in the office on Saturday made a lot of calls at about 4.45pm as they rang home to find out the football results.

He wrote an application that scrolled the results on the IP handsets' displays as the matches finished. Perhaps not the most business-driven use of IPT. but one that demonstrates its potential and eases the pain of weekend working.

How IP telephony can be applied in your LANs and WANs   

Key points to consider include: 

* Examine your business needs - Decide how best to connect branch offices to the central Lan, and what the knock-on effect on the Lan will be. For example, a short-term pay-as-you-go, low-usage VPN service or longer-term solution providing higher, more predictable capacity. 

* Examine the security policy Identify which solution is best for the needs of your individual business. For example, does the data need to be encrypted, or do you need the extra security of a hosted service?  

* Formulate a fall-back plan. Having the option to revert to older systems is important, as is having sufficient back-up in the form of extra lines that connect the branch sites. This initial fall-back plan can also, in the longer term, form the basis for a wider disaster recovery plan.  

* Define the network and implement a pilot. This will enable you to flag up early faults, costs, differences from the old system, performance, etc.  

* Roll out, manage and improve. Ensure good trouble shooting techniques are initiated during the early stages of the complete network roll out and that adding extra services and users to the network will be straightforward.   Quality of Service (QoS)  Ensure QoS is monitored both objectively and subjectively. This will ensure you get exactly the level of service detailed in the SLA.

Will IT managers have to learn new skills for the IPT world?   

"They will have to develop an understanding of how voice impacts their network and plan for it."   Dave Millet, business development manager across EMEA, Avaya 

"In addition to establishing the business case and return on investment, IT managers should carefully consider potential personnel and training issues that may arise as staff get used to the new systems."   Lucy Green, product marketing director, NTL business division 

"IT will need to develop an understanding of telephony, but teaching is readily available. Developing the right skills will be a gradual process as companies move towards IP telephony."   Mike Valiant, international market development manger for enterprise voice solutions, 3Com 

"We can reduce our reliance on expensive telephone consultants. Training for my staff is Windows-based and fairly straightforward."   John Brogan, group IT manager, Four Seasons

Case study: IP - core to the business or just nice to have?   

When care home and hospital management company Four Seasons moved to centralise its administration and accounting function into a new office in Darlington in the summer of 2003, John Brogan, the group IT director, was charged with managing the installation of a new communications system.

"Having read about the savings possible through IP telephony, I decided to investigate," he says. 

Working with BT, Brogan decided to put in a converged network based on Cisco AVVID technology. BT now manages the system and provides the security measures to ensure patient records remain confidential. 

Brogan's initial reason for adopting IPT is to reduce the cost of telephone calls between the 350 care homes, hospitals and offices that make up the group, by sending voice traffic over a secure wide area network (WAN). "We have just finished broadband enabling all our sites. The next stage is to look at IP-enabling them," he says.  

Currently, the head office in Wilmslow, Cheshire, and the Huntercombe Roehampton Hospital in south west London are the only other two sites to have been upgraded to use IP telephony.  "It is very straightforward, requiring only the installation of a Cisco 2651 IP-enabled switch onto the existing data network and rather than having to install a new PBX system at the site, the only cost is the installation of IP handsets and routers," states Brogan. 

Brogan is not certain how far he wants to embrace IPT, and is pondering whether to adopt a unified messaging application with voicemail and e-mail both being accessed through Microsoft Outlook.   "I'm still not sure how practical it. Is it core or just a nice to have?," he asks.  

And while it is too early for Brogan to give an exact return on investment figure, it's clear the new IP infrastructure offers opportunities for savings. "We have removed the cost of PBX renewal, reduced network maintenance and, most significantly, cut internal call costs between company sites," says Brogan.

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