Magazine Article | June 1, 2003

Give VoIP Some Elbow Room

Source: Field Technologies Magazine

You can reduce telephony costs by routing voice traffic via IP (Internet Protocol). But, you'll have to give network priority to voice.

Integrated Solutions, June 2003

Using IP (Internet Protocol) as the basic network data transmission vehicle has become so ubiquitous that IT departments - even at small to midsized enterprises - have developed deep-rooted IP expertise. Coupled with a "second nature" familiarity with Ethernet-based LANs and WANs (wide area networks), this IP "comfort zone" allows companies to look for additional ways to leverage their in-house networking expertise. One way is to use IP to handle voice transmissions.

Particularly at companies with call centers or help desks, IP-based telephony, specifically VoIP (voice over IP), offers several potential benefits. First, VoIP reduces a company's costly reliance on traditional telephone networks and services. VoIP also enables companies with facilities across wide geographic - even global - areas to implement "follow the sun" call-handling practices. "A company that offers field service, for example, may want to shift calls from coast to coast or from country to country as the day goes on," says Mike Sheridan, director of product strategy and marketing at call center technologies vendor Rockwell FirstPoint Contact Corp. (Wood Dale, IL). "They can now do that using their data networks." Says Bruce Grant, director of product management for marketing and sales support, Corporate Networks Group, at communications systems provider NEC America Inc. (Irving, TX), "IP-based voice technology establishes peer-to-peer communications without sending the actual voice transmission through a PBX [private branch exchange]. VoIP allows you to put a media gateway device anywhere on your global network and route calls as though they're local calls."

That high degree of communications flexibility, which VoIP fosters, can help companies develop mobile workforces. According to Jorge Blanco, VP of product and solutions marketing at enterprise communications provider Avaya (Basking Ridge, NJ), IP telephony solutions supplement wireless mobility initiatives at many growing companies. "We're seeing a lot of companies supporting their mobile workforces or employees who work at home or on flex time with remote access to business telephony capabilities," Blanco says. "We're also seeing companies bringing small, remote locations online with full telephony functionality. IP-based technologies allow them to do that without investing in redundant communications systems at each new location."

Perhaps the most powerful benefits of IP telephony emerge when companies deploy it alongside other communications channels - e-mail, text messaging, Web chat, and so on. In that way, VoIP helps companies transform their call centers into full-service contact centers, with agents handling multiple types of customer interaction. "Using a traditional telephony system, it's hard for the ACD [automatic call distribution] device to know if an agent is actually busy," explains Shane O'Sullivan, senior engineer at speech and voice solutions provider ASA Solutions, Inc. (Scottsdale, AZ). "Even though the agent may not currently be on the phone, that agent may be involved in one or two Web chat sessions. But, if you have the same switch running all channels - including voice - then you can optimize agent utilization, a key part of a call center's profitability."

Of course, reaping any or all of the benefits of VoIP means successfully implementing it. That success will be in jeopardy unless you're willing to take three crucial steps to supporting IP-based voice transmissions.

1. Upgrade Your Existing Networks
You're not ready for VoIP if your data infrastructure can't support the high-level QoS (quality of service) required for voice transmissions. "If you haven't properly tuned the network, you'll get choppy calls, echo, and garbled voices," says Sheridan. According to Blanco, end users need to remind themselves that IP-based telephony is dependent on network stability. "While IP devices have come a long way in terms of quality and reliability, they are still susceptible to network outages and virus attacks, just as your PCs are. So, you need to build resilient, encrypted data networks to ensure the levels of voice service you have been getting in your circuit-switched environment," Blanco says.

While some companies can get by running voice over 10 Mb Ethernet networks, Sheridan and others recommend a 100 Mb network as a minimum. "Typically, a 100 Mb network is enough, but it does depend on how much data traffic you have flowing over it," Sheridan explains. O'Sullivan agrees. "You have to make sure your bandwidth is at least 100 Mb," he notes. "And, remember: if you're going over a WAN, bandwidth can be expensive. If you have many small sites or a chain of sites that need to communicate back to a central office, a traditional TDM [time division multiplexing] environment may still be more cost effective."

Even the physical cabling and switch design come into play. According to Grant, "You know you're not ready for VoIP if your data infrastructure makes extensive use of hubs, if you have layer 2 switches connected to all of your data locations, if your existing PBX cannot incorporate IP-based call routing, and/or if you don't have at least CAT 5 or CAT 6 cabling."

2. Give Priority To Voice Traffic
While companies can try to run voice and data over the same LAN or WAN line, it's likely that, if they do, voice QoS will suffer. That's why it's advisable to segment the network so that voice transmissions and data transmissions run on separate networks. Talk to industry insiders, and the message couldn't be clearer or more universal. Just listen:

Sheridan: "You really have to consider the ramifications of the real-time nature of voice calls. They can't tolerate a lot of network congestion. So, our customers are segmenting off traffic that's specifically voice."

Grant: "People can generally wait for data packets. But, because voice is real time, you have to give it higher QoS than you would e-mail, for instance. So, segmentation in network design is a critical issue. You many need to disconnect, say, 50 user stations and create a new LAN segment for them."

Blanco: "You can potentially squeeze voice through on a shared LAN, but, for large enterprises, that raises a red flag in terms of potential network bottlenecks."

O'Sullivan: "You can't expect to run VoIP on your existing data network. If you do, you're setting yourself up for failure. Make sure you're using segmented LANs."

3. Perform A Network Assessment
Probably the biggest mistake companies make in bringing on VoIP is underestimating the bandwidth limitations of their current routing designs. If they have long since smoothed out bottlenecks for data traffic, they may believe that bandwidth problems are behind them. But, unless the company has thoroughly tested its ability to add voice applications to other bandwidth-devouring apps, its voice transmissions are likely to suffer from poor quality. Voice packets will be dropped; delays will occur. "You don't want to walk into an unknown network and try to deploy VoIP," says Grant. "You might have an application out there that misuses QoS functions or doesn't use them at all. That application may override the QoS levels set up for the voice traffic."

Some of a company's existing call-handling functionality may not work in an IP-based voice environment - not without tweaking or potentially not at all. O'Sullivan notes speaker verification as one function that requires particular attention during the initial network assessment. To give callers access to secure information (e.g. bank accounts, healthcare records), speaker verification systems match the caller's current utterance to encoded voice patterns stored in the system. "A lot of those applications are tuned for TDM environments," says O'Sullivan. "If the encoding was made in a TDM environment, the IP-routed version of the caller's voice may be different enough that the caller may be denied access."

Finally, Sheridan offers the reminder that getting over network integration hurdles is just the first step to implementing VoIP. Next comes the retraining of people who actually take calls, particularly if those calls will now be merged with other communications channels. "Crawl before you walk," Sheridan advises. "Remember, different skill sets are required to handle e-mail, for example, than are required to handle voice contacts. Some people speak much better than they write, and vice versa." However, as O'Sullivan points out, once those training issues have been worked out, VoIP increases the possibility of generating optimal productivity from a multichannel center. "Once you go to VoIP and have the same switch running all of your contacts, you can control agents' activities based on their skill sets," he says. "Plus, you'll have fewer call center silos, with products coming from different types of manufacturers and requiring different skill sets to use and maintain them."