VoIP, instant messaging, streaming video and other multimedia data running on converged networks offer businesses numerous benefits, including lower costs and more efficient management.

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By JD Sartain

tech journalist, mslsec.com |

Networks today must evolve into a robust, services-oriented platform that enriches emerging, innovative, composite applications and yet still manage to balance technology and business processes. In addition to its primary function—that is, data—converged networks incorporate instant messaging, multimedia e-mail, voice and streaming media, Web and videoconferencing, unified collaboration, and more. Enterprises can finally consolidate resources in a shared environment for higher levels of utilization, lower costs and more efficient management.

Enterprises are no longer saying if, but when. According to Leslie Davis at Brocade Communications Systems Inc., the converged network offers compelling benefits that involve increased levels of utilization for the resources in the data center while also reducing the equipment and management costs of the network itself (compared to an architecture that is not converged). Consolidation also provides an advantage in power and cooling efficiency in the data center, where reducing the number of systems in an environment lowers the consumption of electricity and reduces the need for HVAC, both of which provide cost and environmental benefits.


"The clear advantages of converged networks are improved costs and IT resource productivity," says Ben Gibson, senior director of mobility solutions at Cisco. Convergence shifts the focus from reactive case management to proactive innovation delivery, he notes. By managing one network and converging data, voice, and video applications over that network, the stress and frustration of managing disparate networks, applications, and protocols subside.

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"With video, voice and network technologies starting to blend, it became clear that we could gain efficiencies by merging together our professional resources that were designing and operating those networks and then merging the physical networks together," says Erik Parker, senior infrastructure analyst of wireless and LAN infrastructure design at Toyota Motor Sales.

Toyota Motor Sales deployed to more than 1,200 different sites a Cisco-based network solution that provides a standards-based network, allowing it to easily supply video, data and voice over the same physical network. Using this configuration, the converged network allowed Toyota to deploy any Internet protocol–based application without having to add any physical hardware and still ensure the reliability and redundancy of the network.

According to Parker, this strategy has allowed Toyota"s individual resources to share their expertise in what used to be silos of technology, with other like-minded resources, resulting in a more resilient team of engineers. Once the merging of the physical networks is complete, Toyota"s engineers can more easily deploy the plethora of voice, video, media-rich applications and collaboration tools. "Having the proper backbone in place makes it exponentially easier and considerably quicker to start rolling out the more demanding applications that an enterprise requires," says Parker.

The advantages are undeniable and acutely evident in numerous areas, including capex (capital expenditures) and OpEx (operational expenditures) savings, notes Gregory Heath, director of solutions marketing at Extreme Networks, Inc. Among other advantages, the converged network allows voice calls to take advantage of toll bypass; it saves on the costs of building a separate, circuit-based network alongside the data network—from PBX to cable plant (wiring); supports multiple advanced features (far beyond circuit phone systems); and reduces the staff needed for IT and telecom. (Also read 5 Things You Need to Know About Unified Communications (BeforeYou Start).)

Bob Mays, director of network and communications at Villanova University, says, "Last year, the university partnered with Avaya and Extreme Networks to install an IP-enabled PBX with VoIP capabilities. Now, we can manage both the voice and data networks using one platform, which is a better utilization of staff because both the voice and data network teams can troubleshoot the same network. In addition, it positions the university to begin saving on long-distance expenses when outbound calls are going over the Internet."

Villanova is on a second-generation converged network built with a network foundation from Extreme and IP telephony solutions from Avaya. The network connects more than 3,000 IP and digital phones, providing flexibility for staff. Staff members use feature-rich IP or SIP phones as buildings are updated on a rolling technology upgrade.


As with any architecture, notes Davis at Brocade, there are pros and cons. One possible con of converged networks is the increased complexity of managing multiple traffic types and the service levels for each, compared with a dedicated network model, where sharing is not a consideration. With any architecture that shares resources among multiple functions, the possibility of contention for resources exists. That"s why features such as adaptive networking are vital in converged networks, because administrators can set policies and rules for services levels, end to end, through the converged network. This makes management easier while also enforcing the service levels, so users of the network experience the same level of service as if they were on a dedicated infrastructure.

"In addition," says Davis, "While some organizations could consolidate mainframe and open systems connectivity on platforms they already have deployed, they choose to keep these applications separated on dedicated network infrastructure for reasons of business rules, oversight and ownership, and/or organizational preference. Keeping the networks separate means they can maintain proven operational and organizational ownership and processes that would otherwise need to be reengineered in a new model."

"Another potential disadvantage of a converged network is the dependency on a single infrastructure," adds Heath at Extreme Networks. "This makes resiliency and reliability vital. In addition, a modular software operating system is also a key factor because it provides reliability through the separation of processes, hitless software upgrades and the simplicity of the same OS employed across the switching product portfolio, which minimizes human error."

According to Heath, less than 50ms path protection failover is a requirement on voice networks, a condition that may not have been imposed on the network before convergence was introduced. The Ethernet Automatic Protection Switching (EAPS) protocols can meet this need to keep a voice call up and active, even in the event of a fiber cut or interruption. Quality-of-service (QoS) prioritization for data, voice and video also becomes more important.

"It"s not a disadvantage," says Mike Babin, assistant director of communications/IT department at Concordia University, "But two areas that still need improvement are teleconferencing and video conferencing. We use the former for teaching and meetings and the latter for classroom training. Both are extremely difficult to support and require an expert staff on hand to manage and troubleshoot the process. Otherwise, we are quite happy with our converged network."

Concordia University has a standard Cisco architecture core/distribution access layer network on two campuses with 30 buildings per campus. The two cores on each campus are each 6500-class switches, and 4,000 telephone lines (with only 150 leased from the phone company; the rest are VoIP). They have a wireless network with about 360 access points (indoors) and 40 or so for outdoors (60 are 802.11, draft-2 compliant). "In terms of the network," says Babin, "We currently have the capacity to support any of the converged apps."

Boiling It Down

According to Dennis Drogseth, vice president and analyst at Enterprise Management Associates, the volume of traffic over the networks today is predominantly application traffic—largely Web-based applications, followed by client/server. VoIP is still a relatively small percentage, whereas, for instance, service-oriented architectures (SOA) are rising. And while voice, streaming media and other technologies appropriately get the concerns of the network community, Web-based applications and Web 2.0, in particular, are increasingly posing a challenge, as the network is becoming virtually a "backplane" for applications.

"Virtualized environments, as the network needs to route between VMs (virtual machines) geographically dispersed in support of a single application, are also going to create challenges to network managers," says Drogseth. "So my point is that the "converged network" discussion is a bit parochial, focusing on voice, media, and data with voice and media getting the limelight when, in reality, the converged network will still be primarily about managing application traffic effectively in an increasingly virtualized universe."