Deployment Strategies for IP-Centrex

The arrival of credible IP-Centrex services presents different scenarios to corporate decision-makers, depending on the state of their telecom infrastructures and on the alternative offerings in their marketplace. These situations fall into one or more of three classes:

1. Controlled Migration to IP-Centrex. Many organizations will wish to add IP phones to an existing Centrex configuration (i.e., the hybrid approach). Two possible reasons for this might be:

- To implement a contact center as a managed service;

- To extend fully featured, multimedia service to remote or mobile worders.

For these solutions the organization will need to use a wellmanaged IP network, which may be provided by the ILEC, that currently operates the Centrex service, or may be from another service provider (e.g., an international telco with a wider-ranging network, such as AT&T or BT).

The use of two or more IP-WANs presents a further choice to the customer, as the customer may prefer to have access directly to the competitive long-haul network through a switch at the customer's site, rather than via the IP-Centrex service provider's own network access. This alternative is shown in Figure 1.


Figure 1:Controlled migration to IP-Centrex.

2. Greenfield IP-Centrex Implementation. On the reasonable assumption that the average digital PBX needs to be replaced (not just enhanced) after a 10-year life, or that long-term Centrex contracts never last more than a decade, about 10% of all organizations will face a crucial greenfield telephone services decision each year.

3. Move to a Competitive Service Provider. Many organizations obtain their Internet or VPN connections through an ISP and/or rent Web server hosting facilities from a service provider other than the incumbent telco. In many of these cases this service provider is a good candidate to become the customer's communications application service provider (CASP), in preference to the ILEC.

When considering whether or not to entrust its in-house voice and video communications to a CASP, an organization's management must evaluate the following topics:

- The specific IP-Centrex design being deployed by the CASP;

- The match between the feature set available, from the competitive IP-Centrex service, and that needed by the users;

- The local access technology being offered to the WAN and its scalability to accommodate growth (or, occasionally, contraction) of bandwidth needs;

- The perceived financial stability of the service provider, in a time when the finances of some long-established, large telcos also have been seriously questioned.