Centrex - A host of IP-PBX service

Centrex, also called "hosted PBX" is a telephone exchange (telephone switch) remotely hosted VoIP service provider (or ITSP) who offers a service for companies.

Centrex service existed as a remote for conventional telephone lines, and was now suitable for VoIP communications. Centrex software is part of the ITSP's SIP server. Asterisk, an open source freeware for IP-PBX allows the partition of the server to host multiple companies / users.

Each company that hires the service receives a partition of the SIP server and is assigned to a group of numbers that serve as extensions. Extensions are communicating with each other as if they were within a company and receive a corresponding numbered typical short extensions. CENTREK with the services offered are identical to those of a telephone / telephone switch, including all services as normal preatendedor, call waiting, ACD, IVR, among others.

A user of a Centrex service might think that using a central / switch convention. The same applies to a person outside the company, which does not notice the difference by calling from abroad.

Makes sense for Centrex:

• Short-term business projects or
• Companies that want to migrate to VoIP, but want to experience its benefits and disadvantages
• Companies that can not afford the investment of an IP-PBX
• Companies that suffer strong fluctuations in number of users

A list of firms offering Centrex can be found here below:

Centrex provider charges a base rate per month extension. Additional services are charged as options. The customer can configure all your configuration via a web interface. Companies that use Centrex should have a good Internet connection. The ITSP recommended connections for voice and data separate. The hardware you need is a user of Centrex

• A multi FXS Gateway (if you use conventional phones)
• A switch (if you use IP phones)