Reach out and touch the net

Cisco offers a line of gateways that support VOIP

VOIP might be the future of agency comm systems, but it's still best to get there at your own pace

Voice over IP, the technology that uses Internet Protocols to transmit phone calls over data networks instead of over the public switched telephone network, may finally be ready for enterprisewide deployments. Having largely overcome the notoriously funky sound quality and poor reliability of its early years, VOIP now has a place in the telecommunications plans of nearly every federal agency.

The Defense Department has been an early adopter, employing VOIP in numerous pilots or implementations for everything from quick-and-dirty phone networks in military theaters, to administrative call centers, to headsets that allow fighter pilots on anti-terror reconnaissance to dial directly into the Centers for Disease Control and Prevention.

Other federal agencies, including the Environmental Protection Agency, and numerous state and local agencies have recognized that VOIP and related IP telephony tools are an economical way to connect thousands of users, be they desk-bound staff members, telecommuters or constituents.

Preparations to procure these systems should involve learning from others and understanding the technology developments that have made VOIP a viable tool. While concerns over the still-nascent technology may linger, a carefully researched request for proposals should garner the system designs necessary to realize the benefits of VOIP and minimize risks.

Info assurance, reliability

While VOIP has made inroads in consumer and commercial markets, government agencies, not surprisingly, have been nervous about security and reliability. They're conserned about injecting new technology into their tried-and-true phone systems'technology that runs on mission-critical data networks they've already invested heavily in.

'They're not comfortable enough with the new technology to put people's lives on the line,' said Jim Hill, federal systems engineer at Nortel Government Solutions in Fairfax, Va., referring specifically to military hospitals.

And that's understandable. Few people claim, even now, that VOIP is ready to take over the world. 'One of the things it is not is a direct-drop replacement for the PSTN,' said Bruce Fleming, chief technology officer of Verizon Federal Network Systems in Arlington, Va., a network integrator that partners with VOIP hardware vendors.

For agencies starting out, Fleming recommends targeting VOIP for routine administrative traffic. 'Anything that's nonessential, noncritical and nonproprietary.' From there, agencies can grow the platform.

Finding the best place for VOIP in an existing telecom system can be complicated by legacy private branch exchange (PBX) hardware and a motley mix of fax machines, phones, modems and conferencing equipment. Almost all vendors cater to such mixed environments with IP-based PBX appliances and servers, which are gateways for tying legacy devices to the VOIP routers and switches that anchor the network backbone.

The proving ground

But support for old hardware might not live up to the product hype. Experts say there isn't yet a wealth of real-world knowledge about running the legacy side of these new gateways, so IT shops should make sure vendors can demonstrate their products' integration abilities, either in real-world deployments or lab settings.

Another concern is the way some existing firewalls handle voice traffic. 'Voice over IP traffic does not flow through a firewall without an application-layer gateway being present,' said Todd Lattanzi, product manager for Adtran Inc. in Huntsville, Ala.

What all this means is that a VOIP deployment requires a detailed migration strategy that focuses on hardware and software for easing the transition between traditional PBXs and IP telephony, makes both work together and ultimately sets up your agency for future rollouts. 'We have seen a lot of customers that are migrating their current platform to give them the ability to swap out,' said David Ensor, federal sales vice president for Avaya Inc. of Basking Ridge, N.J.

'The question today is, do you put in an IP soft switch capability, or hardware?' Hill said. Soft switches, PCs running special software designed to broker call control between the older, circuit-switched networks and the packet switching of VOIP, have trouble with number portability, especially in networks that follow the established time division multiplexing standard for voice data streams. IP soft switches may therefore work better in so-called 'green-field' installations, which start from scratch. Because some TDM features do not translate directly into IP-PBXs, Hill recommends upgrading existing switches to support both standards.

Escaping OMB scrutiny?

The good news may be (for now) that VOIP has largely escaped the budget scrutiny of the Office of Management and Budget Exhibit 300 process. 'The telecom folks have not gotten the charge,' Ensor said. He considers telecommunications budgets a sacred cow in agencies, but said that as voice increasingly becomes viewed as an IT service, that could change. 'It forces telecom to talk return on investment,' he said.

The business case for VOIP could comprise several factors, including current applications of the technology, emerging standards and attention to service levels.

Communications survivability, a hot topic in the wake of recent natural and man-made disasters, is both a potential shortcoming and strength of VOIP. Without a doubt, a poorly executed VOIP network, lacking redundancy and alternate routing strategies, could be more vulnerable than established systems. But VOIP could also function today as a legitimate backup for traditional PSTN.

'IP telephony will allow the telephones to find an alternative route to the alternate data center,' said Hank Lambert, director of business development for Cisco Systems Inc.

Several experts also point to IP trunking as a way to exploit current VOIP technologies for short-term gains. IP trunking lets enterprises tie together geographically dispersed sites over a single IP link, rather than going through expensive gateways to the PSTN.

In the near future, an emerging VOIP standard will make the technology more than just a phone system. And when agencies can heap additional capabilities onto a business system, it becomes easier to cost-justify the IT investment.

Session Initiation Protocol, a method of initiating, modifying and terminating multimedia sessions, has quickly become the standard for VOIP communications. It is gradually replacing H.323, the incumbent standard that still enjoys widespread support in many platforms.

SIP features are already playing a role in transforming VOIP into a unified, multimedia messaging system that can include videoconferencing, instant messaging and whiteboarding. SIP is critical to these types of communications because it includes what is commonly referred to as presence detection technology. Presence is a feature that knows when people are willing and able to communicate in real-time. It has its humble beginnings in IM systems, where it still takes the familiar form of a buddy list.

In a VOIP system, SIP and its presence technology can make workers more productive by eliminating phone tag. A VOIP user will always know when someone is available to receive a call. The most significant impact of presence may eventually be felt in contact centers, whose efficiency models depend on when agents become free to take calls.

There's currently no industry standard SIP'groups are still working on a specification'in part because leaders with de facto standards, such as Cisco and Microsoft Corp., jealously guard the value of presence in their product strategies, Ensor said. So make sure an RFP fully explores the possibilities and compatibilities of SIP to ensure your agency can get the most from its VOIP system.

Finally, any business case for VOIP would be dramatically undermined if the system couldn't guarantee an acceptable level of service. Hill said that when formulating RFPs, government buyers need to pay more attention to quality-of-service techniques, instead of just throwing bandwidth at VOIP systems to ensure they work properly. The latter approach is one he's seen at several large agencies, including DOD. 'At some point,' Hill said, 'they're going to have to stop doing that.'

One reassuring quality-of-service technology, he said, is Differentiated Services (commonly know as Diffserv), a method for classifying large-network traffic and using service-level agreements to guarantee the volume and speed of each class. Another tool he recommends is Power over Ethernet, which keeps electricity flowing to VOIP equipment that normally isn't powered, like traditional phone lines. And it's best to back up POE with a heavy-duty uninterruptible power supply that sits in a network closet.

Check for certifications

So where does an agency in search of a VOIP system look for government-grade products? For now, the closest thing to a de facto clearinghouse is DOD. The Defense Department's Joint Interoperability and Test Command runs a certification program that helps ensure VOIP products meet certain interoperability, performance and security minimums prescribed in two standards called PBX1 and PBX2.

The stricter PBX1 standard, which is strict enough to OK VOIP equipment for command-and-control systems, includes testing for Multilevel Precedence and Preemption. MLPP allows high-priority users to break through regular voice traffic during emergencies'an important consideration when building a VOIP infrastructure. 'It's an HOV lane for the chain of command,' Ensor said.

Although other agencies are free to adopt these strict DOD standards, they aren't required to. 'Not everyone takes what the JITC has done and says, 'What's good for DOD is good for me,' ' Ensor said.

At the state and local levels, buyers have less stringent requirements, and seem satisfied with off-the-shelf VOIP hardware, Lattanzi said.

Whatever the case may be, experts emphasize that users will determine an agency's adoption of VOIP. Whether it's building the business case, writing the RFP or actually choosing a system, VOIP is not a technology that people should adopt for technology's sake.

'Before you buy, do it in reverse,' said Verizon's Bruce Fleming. 'Don't do any network design at all until you understand what your user requirements are.'

David Essex is a freelance technology writer based in Antrim, N.H.


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