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Networking for Voice, Video, and Data Integration

Enterprises continue to plan and evaluate the convergence of corporate communications over the IP infrastructure. IT organizations (ITOs) must pay close attention to the readiness of the underlying network infrastructure to ensure the highest level of availability and best possible end-user experience.
Written by Chris Kozup, Contributor

Enterprises continue to plan and evaluate the convergence of corporate communications over the IP infrastructure. IT organizations (ITOs) must pay close attention to the readiness of the underlying network infrastructure to ensure the highest level of availability and best possible end-user experience.

META Trend: IP voice will be considered an alternative in WAN applications (toll bypass and access reduction) and campus implementations where high voice costs, unique phone-based applications, and in-house management are primary drivers (2003-07), but will not catalyze wholesale PBX replacement through 2007. IP centrex will suffer from minimal user functionality and unattractive pricing. Speech-enabled applications (e.g., speech recognition, text to speech) will enter the mainstream in 2003/04 and expand to incorporate multimodal clients (speech plus non-PC), resulting in more intuitive and flexible information access by 2005/06.

Our recent study, “Enterprise Convergence 2003: Trends and Issues,” shows that enterprise migrations toward converged communication infrastructures have not accelerated at a significant rate during the previous two years (when compared with the 2001 study). However, ITOs continue to invest in various ways to prepare the business and infrastructure for what is now accepted as an inevitable migration from traditional TDM (time division multiplexing) telephony networks to single IP networks capable of supporting a multitude of applications and services. At the foundation of any convergence planning are the campus and wide-area networks. ITOs should take steps today to prepare these networks for the higher demands that real-time mission-critical applications bring.

Leading convergence vendors (e.g., Avaya, Alcatel, Cisco) have developed network audit services to ascertain the readiness of the underlying enterprise infrastructure for convergence. We consider this type of analysis to be essential prior to embarking on convergence deployments, as the readiness of the network will have a significant impact on the total cost of converging voice, data, and video. Our research indicates that only 51% of large enterprises (1,500+ users) currently have a completely switched IP LAN to the desktop. The remaining enterprises have some degree of shared networking - an immediate inhibitor for voice over IP (VoIP). Of the large enterprises, only 9% indicated that they had made the complete migration from TDM-based telephony to VoIP, yet 35% claimed no current plans to migrate - a significant increase from 5% in 2001. Indeed, we have seen such backlash within our customer base as users struggle to adjust internal processes and as many vendor solutions continue to lag in stability and feature set. Through 2004/05, network architects and strategists should focus on building a network infrastructure that will be optimized for voice, video, and data applications. Broader enterprise migration toward voice and VoIP will continue to be dependent on greenfield build-outs and legacy product refresh. By 2008, we estimate that 50% of enterprises will have significant production scale IP telephony deployments.

High Availability
Of 206 survey respondents, 80% indicated that they anticipated running voice, video, and data over a single physical infrastructure as opposed to maintaining two separate networks. This emphasizes the need for high availability as a key characteristic of a converged communications infrastructure. Although it may be tempting to view high availability as being largely a function of component redundancy, we advise ITOs to take a broader view into how vendor viability, product interoperability, power, management, process, and organizational change management can also negatively impact high availability.

Converged Infrastructure Sourcing
Survey respondents totaling 71% indicated that they prefer sourcing best-of-breed components as opposed to single sourcing from any one vendor. Lack of interoperability between telephony systems will force users to single source. Although the presence of standards is much greater in the data network, we continue to see customers decreasing the number of network suppliers. There is little technical advantage in single sourcing both voice and data, and believe users should push vendors for open standards as they relate to how voice runs over the data network. Despite initial claims that IP would bring telephony to open standards, IP telephony vendors continue to embrace proprietary protocols and features and, in some cases, even proprietary links between voice and data infrastructure. Of 239 respondents, 44% indicated that they would not wait for standards ratification before undertaking an IP telephony migration. By 2005, leading VoIP vendors will drive standards (largely through SIP) to allow for the addition of third-party telephony devices (e.g., PDAs, soft phones, smart phones).

Architecting Accurately
Various different converged communication architectures have emerged. The major categories are traditional PBXs with IP extensions, hybrid TDM and IP systems, and pure IP server-based telephony systems. Of 114 large enterprise respondents, 59% indicated a preference for traditional PBX with IP extensions versus 38% who favored an IP server-based approach. We believe an architecture that allows for ease of migration to be the most viable approach for the majority of enterprises. Given the installed base of PBX infrastructure, it becomes imperative that any new IP-based system be able to seamlessly integrate with the existing solution. The internetworkability of IP allows for next-generation telephony systems to be architected in more of a decentralized fashion than before. The IP network becomes the switch, with call processing and applications residing in separate servers distributed across the network. Users must be very careful in their architecting, as the distributed nature of these resources could potentially have an adverse effect on performance, quality, and availability.

Vendors continue to consolidate feature functionality into fewer platforms. A primary example of this is branch-office products that have evolved from pure telephony servers to support telephony, LAN, WAN, and security capabilities. Many vendors (e.g., Nortel, Avaya, Alcatel) offer branch/remote office products capable of providing the majority of voice and data communications, along with security and management functionalities required for that location. This convergence is also seen in the area of collaboration and communications, whereby IP becomes the common thread across Web, voice, and videoconferencing. As a result, the underlying infrastructure must be flexible enough to support different interaction applications. Cisco’s acquisition of Latitude and Polycom’s acquisition of Voyant are clear examples of the infrastructure consolidation that is occurring. However, enterprises should not expect a single infrastructure capable of supporting the complete range of unified communications (e.g., voice, video, Web, IM, data) before 2007/08.

Network Services
The network must evolve to support the additional requirements of a unified communications application portfolio. Security, quality of service (QoS), power over Ethernet, and wireless are all network-layer technologies that will play a key role in the delivery of a scalable, reliable converged communications infrastructure. After product cost and lack of budget, security was the most common reason the 238 respondents identified as causing a delay in the migration toward a converged infrastructure. Furthermore, QoS remains complex, with only 18% of enterprises currently enabling any type of QoS across the LAN. With the power over Ethernet standard now ratified, ITOs may build greater reliability into IP telephony systems by centralizing power provisioning. However, the cost of backup power supplies to wiring closets and switches will significantly increase the cost of providing similar power resources when compared with traditional systems. User demands for mobility have been felt by the large majority of companies. The immaturities of IP telephony, along with those of enterprise wireless LANs, will limit the larger scale adoption of Voice over Wi-Fi before 2008. However, 57% of respondents indicated that wireless was a part of the overall converged communications infrastructure.

Business Impact: As the business reliance on communications increases, careful evaluation of infrastructure projects is critical to guaranteeing smooth business operations.

Bottom Line: Successful IP telephony projects involve careful evaluation and consideration of the readiness of the underlying network infrastructure to support real-time, mission-critical applications. Users must enhance the network as appropriate irrespective of whether IP telephony deployment is imminent.

META Group originally published this article on 4 March 2004.

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