A recent report by Allied Business Intelligence predicted that premise-based (IP PBX) voice over IP (VoIP) gateways will grow from 4.3 million ports in 2001 to 47.6 ports in 2007. (See chart.) VoIP uses a TCP/IP network for the transmission of audio signals, enabling an enterprise to use an existing network for its telephone system rather than a separate PBX.
"To go out and buy a new circuit-switched PBX now is investing in a dead-end technology," says Raymond D. Keneipp, Vice President of Networks & Telecom Strategies for the Burton Group. "I think that everybody has accepted the fact that we will end up with a converged infrastructure. It's only a question of are you going to do it sooner or later."
As with many establishing technologies, a realistic approach to VoIP's advantages and disadvantages is beginning to replace the initial--and sometimes irrational--enthusiasm of the early adopters. For example, one of the highly publicized selling points of VoIP has been the promise of significant savings on the cost of long distance using toll bypass. However, while some savings are possible, the true cost advantages are difficult to assess, especially for enterprises, whose long distance charges have already shrunk through dropping rates, calling plans, and existing PBX toll bypass.
A more realistic benefit is the consolidation of your current network infrastructure to support both data network and PBX functionality, which can result in operational savings, especially in offices where relocating employees and reshuffling facilities is commonplace. Rather than having to install a new phone and possibly even rewire for adds, moves, and changes, employees can just plug a phone into a network jack, or just log on from their PCs using specialized software at the new location.
Consolidation, however, can also mean a strain on bandwidth, depending on your organization's current setup. Companies that add an IP PBX can expect that some upgrades will probably be necessary. For example, you may need to upgrade your routers and/or router software, add more servers, or upgrade your protocols.An IP PBX may demand increased bandwidth, but it is also far more flexible than current circuit-switched PBX systems. For example, while an overloaded circuit-switched PBX system will invariably require the purchase of new equipment, an existing IP PBX can piggyback on adjoining T1 or T3 lines to take up the slack.
In addition, the installation of a solid Quality of Service system, which prioritizes the packets passing through a network, can handle performance problems due to increased network traffic, although it cannot make up for insufficient bandwidth. If necessary, many enterprise VoIP gateways can fall back automatically to existing public switched telephone network (PSTN) connections, instead of routing calls through the Internet, when the system is temporarily stressed.
The greatest return on investment from VoIP is the most difficult to quantify: Increased worker productivity through a variety of new applications and services that are only now becoming available on VoIP systems.
An IP PBX system offers consolidation of your data/voice/video, providing a means for users to assert more control over their use of phone features using a desktop GUI. Although some of these applications are already in place on circuit-switched PBX systems (albeit in a less friendly format), they can only be used with a dedicated call center, whereas VoIP systems allow any user to access these features. Some VoIP systems, for example, let employees log on to the system anywhere on the network, and immediately route incoming calls to their station, along with appropriate data. Unified messaging combines and tracks e-mail and voicemail on the same Windows screen, allowing users to keep call journals, record/cache calls, identify callers, easily set up scripts for filtering and call routing.
So while Keneipp advises enterprises not to do a forklift upgrade, gut their old system and put in a new one, he does suggest they investigate VoIP if they are installing telecom gear at a new site or have outgrown their old PBX. Enterprises that aren't ready to switch yet, but are planning network upgrades, should keep in mind that the odds are that their networks will need to accommodate an IP PBX sometime in the future.