Advantages of IP-PBXs

Advantages of IP-PBXs
The relative importance of the advantages that are claimed for IP-PBXs (as compared with legacy digital PBXs) has changed since these systems first appeared in 1997, but the claims are now fairly consistent among the IP-PBX vendors. The positive aspects of IP-PBXs can be summarized in the following points:

- Use the same Ethernet networks for all forms of telecommunications. This immediately means eliminating the need for separate data and voice cabling installations and, ultimately, for any voice-only wide area connections.

- Simplify the MAC tasks, since an IP phone, with its built-in intelligence, can be plugged into any outlet on the corporate network. Some early adopters of an IP-PBX claim that up to 50% of MACs can be done by users, without the involvement of any telecom professional.

- Use a Web-based browser management package to administer the features and configuration of an integrated voice, video, and data network, from anywhere that has network access. The administration of the corporate telephone system now becomes a function of the IT department, which already has the required data networking expertise.

- Gain access to existing and new applications that run on the organization's network, through an IP phone. Some users may not have access to a desktop PC and others may find it simpler to use a phone rather than a computer. One major law firm, for example, claims that it fully cost-justified its purchase of an IP-PBX because its lawyers were then able simply to use an on-line time-tracking package and bill its clients for more hours in a week.

- Carry intersite voice and video traffic over the corporate data network, and thus do not spend money on long-distance charges that apply to the PSTN.

- Have a centralized, reliable call-processing server, which is the core of the IP-PBX, but do not need to deploy other voice switches at the remote, smaller corporate locations. Since the signal transport cost across an intranet is low, the intelligence can be in one place, even as the packet switches are distributed, and considerable expenditure can be saved.

- An integrated messaging server that is based on industry-standard protocols and processors delivers more storage at much less cost than a proprietary voice mail system.

The issue of replacing TDM-based PBXs, or legacy Centrex, with an IP-PBX is not nearly as clear-cut as these seven advantages might suggest. We can find at least one counterargument to each of these points. For instance, the toll bypass justification for VoIP is not now nearly as powerful as once it was.

The fall-off in PBX sales over the past few years has been partly caused by the economic slowdown, but undoubtedly also results from uncertainty regarding the viability of IP-PBXs and their place in corporate plans.