The acronym Centrex ( Centrex ) is a two-word compound word — centr al ex change — literally — the central switch (or exchange, interaction in the center ) and refers to the form of telephone communication.
Centrex - centralized PBX / PBX services for business that are provided by a telephony provider, that is, a telecoms operator and which correspond to the capabilities of corporate office PBXs (Private Branch eXchange PBX ).
Telecommunication equipment responsible for call management and additional service functions is located in the premises of the telecom operator , belongs to it and is operated by them to provide services to Centrex. Typically, this equipment is the company's central telephone switchboard, hence the name.
The customer gets rid of the need to own a very expensive telephone station (or rent it), which not only frees him from large initial investments, but also changes the structure of current costs. The operator charges the services provided, depending on the number of subscriber lines served, which may change over time as well as upwards and downwards.
From this point of view, centrex is a typical example of outsourcing in the field of telecommunications .
This package of telephone services of telecom operators is very popular in organizations since the second half of the 20th century. Since the beginning of the two thousandth, along with intensive empowerment
Telecommunications services Centrex found a new technological basis and further development.
Technical Description
The key feature is that initially the operator switches of the public telephone network served exclusively to automatically search for the route of the call and establish a connection between the subscribers. Similar functions were performed by the internal small PBX organizations. However, the development of telecommunications equipment by manufacturers allowed to provide users with new service capabilities ( DVO ). Thus, subscribers of public networks belonging to the same organization (and, as a rule, served in the same building), who are provided with Centrex services, received the opportunity to be connected at the switching center into one centrex group with general principles of operation and FEI. Moreover, subscriber terminals can be located in any part of the telephone network served by the equipment of the central switchboard of the telecom operator. At the same time, special fees for additional lines or terminal placement may not be charged remotely.
The central switchboard provides the entire set of subscriber and network alarms, additional services and other telecommunication services that allow subscribers of the public network to join in groups either within the switching node or throughout the network, and within these groups use various additional services that are similar to PBX subscribers.
Each member of the center-group is assigned, in addition to the telephone number in the PSTN , also an internal short subscriber number in the center-group. Typically, a subscriber can have only one internal number and can be a member of only one centrex group. Members of the centerx group are given the opportunity to use the full range of basic services of the subscriber of the public network, as well as additional services or their modifications provided by the centerx group.
The right to use additional services is given to the number of the Centrex subscriber on the PSTN, the same rights are also given to its internal number. Each member of the centrex group can be assigned the limitations of centrex.
As a rule, the centrex group also has a common external telephone number in the PSTN network, which is associated either with the secretary-telephony number of the organization or with any automatic service ( IVR , DISA , Call Center ).
The minimum required set of centrex services:
- use of internal 2 or 3-digit numbers for calls within the office / organization;
- transfer incoming call from the city;
- translation of an outgoing call to the city (a classic example is “Natalya Petrovna! Dial Nicholas to me!”);
- Intercept a call (in a group).
Additional services
Standard Centrex services are necessary for the implementation of key business processes by an organization, by analogy with PBX:
- Call redirection by status - not answered / busy
- Voice mail
- Call waiting or second line (the ability to take a second call while holding the first)
- Conference (from 3 or more subscribers)
- Callback (I will call you!)
- Reminder (who needs to call at the right time) / alarm clock
- List of recently dialed numbers
- Centrex Hotline (connection without dialing)
- Queue incoming, with music or advertising while waiting
- Dialing groups, optionally with one number for a call to a group.
Famous Companies
Major telecommunication companies that have provided and provided services to the center for decades:
- Verizon
- AT & T
- British telecom
Further development
The centrex service package allows an organization or company to completely abandon the acquisition and maintenance of an office PBX in-house, and at the same time enjoy all the advantages of internal telephony, since all the necessary means are provided by a centralized telephone node of a fixed-line operator . This explains the popularity of services in the corporate sector.
Centrex services are easily represented through a “flat” computer network , in particular via the Internet, thanks to the capabilities of IP telephony . This type of service is called IP-Centrex and also, recently, a virtual PBX or "cloud PBX".
A similar package of services can be provided by the mobile operator . On mobile networks, this is usually called FMC (Fixed Mobile Convergence) .
Modern converged universal telecom operators can offer various options for the implementation of centx services, including combining all of the indicated types, thanks to the use of a multiservice NGN -network.
In the US, the use of Centrex lines fell from 16.5 million in 2002 to 10.7 million in 2008, as users switch to IP-PBX and VoIP [1] [2] Centrex services continue to be provided to large commercial companies and government agencies, agencies and universities since the corresponding the equipment has already been purchased and paid for, despite the fact that sometimes services provided by centrex are more expensive than the organization of a communication channel to an individual PBX of the enterprise, if it were (usually absent). [1] [3] [4]
Sources
- Tim Greeny "PBX v. Centrex. 2007 Network World (English)
- Institutional IP telephony from the provider (Rus.) , Open Systems Publishers . The appeal date is April 21, 2017.
- CNews: A well-organized call center is an essential contribution to a positive image of the enterprise.
- Second breath of IP-telephony (rus.) , Open Systems Publishers . The appeal date is April 22, 2017.
- ↑ 1 2 Reed, Brad. Centrex: It's alive (for now)! (Neopr.) // Network World. - 2012. - 13 February ( vol. 29 , No. 3 ). - p . 10 . Archived July 3, 2013.
- ↑ TIA'S 2009 ICT MARKET REVIEW AND FORECAST Unreferenced (not available link) 3–20. The Telecommunications Industry Association (2009). The appeal date is April 22, 2017. Archived May 21, 2018.
- ↑ Hochmuth, Phil . VoIP converts say good riddance to Centrex (September 20, 2006). Archived September 27, 2006. The appeal date is February 22, 2012.
- ↑ Greene, Tim . PBX v. Centrex (October 26, 2007). Archived October 23, 2012. The appeal date is February 22, 2012.
See also
- Telephone number
- Office PBX
- Fixed Mobile Convergence
- Virtual PBX
- Virtual office