Türk Telekom’s Centrex service provides all the features of a telephone central.
For today Centrex service is provided in Ankara and Istanbul and applications can be done to Ankara, Istanbul European Minor and Istanbul Asian Minor Province Telecom Directorates.
Standard features are the user features that are provided to all Centrex subscribers free of charge with the agreement. Some of these features can be used on both digital and analogue telephone devices while some of them can be used only on digital ones.
That every user within the subscriber group will take advantage of which features on what terms, is arranged in the beginning in the direction of the customers demand and no fee is charged for this arrangement. Additions and alterations to be done on the features determined for the users are subject to charging. But for all the alterations made at once other than the ones determined in the beginning, fee that is stated in its tariff is received.
Tripartite conference/transfer feature is a combination of tripartite call and call transfer. It is used for adding a third party to a call by the subscriber.
Call collecting feature provides subscriber to respond the calls for another subscriber within the call collecting group that is determined erstwhile.
It is the feature that Centrex subscriber can redial the last subscriber he/she called without dialling the numbers once again but only pressing a single key.
With this feature, while an incoming call that faces an engaged subscriber get a back ring direction, the engaged subscriber who was called hears a call warning tone. The subscriber who was called either puts the existing party on hold and contacts the new caller or ends one of the calls.
It provides the transfer of a call for a Centrex subscriber to another Centrex Subscriber.
Group Intercom feature provides the subscriber to access to intercom group members that he/she is included by making a shortened dial.
It is the feature putting the caller on hold if the number called is engaged at the moment, when the calling subscriber is connected to the number he/she calls by operator.
Call Diversion feature provides diverting the incoming calls to predetermined numbers. Call diversion can be done in three different ways.
Different customer groups of Centrex can call each other with shortened call by dialling 2-5 numbers as if they are making intra-group call.
In case that the number he/she called is engaged, with redial on engagement feature, Centrex subscriber ensures that the call is performed automatically when the engagement of the called subscriber is over.
Call hold feature provides that a subscriber puts a subscriber he/she calls and makes another one.
This feature provides the equally dispersion of calls incoming to a serial of telephone numbers between a group of subscribers determined earlier.
It provides that when the caller picks up the receiver a predetermined number is automatically connected.
It provides that the very frequently called numbers are defined as a list and can be dialled by dialling the speed dialling code consisting of one or two digits. Short list may contain 10 recorded numbers at most and long list may contain 30, 50 and 70 recorded numbers.
Call park feature provides a call be parked. A parked call can be can be retrieved by dialling the DN number of the subscriber, that it is parked, from some other place.
This feature lets the subscriber hold the active call on his number without the help of the operator.
The user who encounters the engaged status of all trunks is warned when a trunk is available. Then later the subscriber connects to the automatically called number.
This is a feature that Centrex special telephone sets provide its user to reach an engaged subscriber.
This feature provides that an incoming call to primary DN number is automatically answered 4 seconds later. Call is done through hands free calling unit.
This feature provides that very frequently called numbers be dialled by pressing an allocated speciality key.
It is the feature that the DN numbers on Centrex special telephone set are displayed as engaged for the incoming calls other than call on hold, call interruption, ended calls and MADN group members.
It provides that Centrex subscriber be ended directly at pre-identified set by pressing intercom key on special telephone set.
It is the feature of assigning one number to more than one telephone sets.
Special telephone set user can provide tracing back and catching of vicious caller. In cases that caller and called parties are on Centrex exchange; connection continues until the called party resolves the call.
Centrex subscriber puts the call on hold and listens the other party through the speaker. This feature provides the Centrex subscriber to determine the time of re-establishing interview with the subscriber on hold.
Special telephone set user can create and perform a call without picking up the receiver.
It provides the subscriber to programme frequently called telephone numbers to the keys on the set and to dial by pressing a single key.
The subscribers connected to the Centrex exchange sees who calls them as name and telephone number on the display of the special digital set.
The subscriber sees the name and telephone number of the Centrex subscriber he/she calls.
These are the features that are not included in standard feature pack and defined or activated on demand, and given to the user by receiving fees for only once in accordance with the tariff. These features can be used with both digital and analogue telephone devices.
One or several of these features are identified in accordance with the customer's request. In case that the music on hold feature is given, music equipment is supplied by the customer.
