Almost all organisations use EPABX because of the following reasons  :

       Short code dialling for internal communication within the organisation.
       All such calls are free of cost.
       Phone Plus facilities such as call transfer, call park etc. are available.

     But installation of a PABX has the following implications / limitations  :

       Initial investment for the PABX.
       AMC for PABX equipment.
       Require some air-conditioned spaces.
       Concentration of traffic towards PSTN.

     New CENTREX facility of BSNL relieves from all these implications / limitations without

     Sacrificing any of the above facilities  :

       In CENTREX, no physical PABX needs to be installed.
       Facility can be extended to any ordinary telephone.
       A special dial tone which is different from the normal dial tone is provided.
       A number of such lines can form a group called CENTREX group.

     Like a PABX, following dialing procedure is adopted :

       For internal call (call within the group), dial a 2 or 3 digit number.
       For outgoing call (to call outside the group), dial '9' - get normal dial tone-dial Local/STD/ISD digits.
       For incoming call - a CENTREX number can be reached from outside the group by dialing the 8        digit directory number.

CENTREX , a real friend of the frequent caller... Choose a number you want to talk to in unlimited way. Choose two number you want to talk to without seeing your watch. Choose three or more numbers you want to talk to without caring of time. Form a CENTREX group with these numbers and go on talking. All such calls of any duration are free of charge.

     TARIFF

     How to apply

      Application to be submitted to Area Commercial Office with the following details :

      Telephone Number of applicant (Leader of the group)
      Declaration from the leader of the group that he will pay the CENTREX charge for  the entire group.
      Telephone Number of other members.
      No objection from other members.