21CN is BT's next generation telephone network - an advanced end-to-end IP-based network.  Please use the link above to find out more in-depth about 21CN.

A couple of general questions are answered here:-

Dialling Types
There are two methods of dialling.  Tone and pulse.  Pulse dialling is just like using an old fashioned dial.
BT state that they will be keeping both of these methods of dialling with 21CN.

Subscriber Meter Pulses
Meter Pulse is a method is sending, in real time, a signal to the customers equipment every time a meter pulse is generated during a call.  This facility is used by Hotels and other organisations for real time billing on analogue exchange lines.

CN21 will not have this facility.  Click here for the BT Statement on this product

This will stop the generation of real time billing on customer equipment.  In some cases the customers equipment can be programmed to Psuedo metering, which is where the bill is generated using system parameters.  Older Mitel kit such as the SX10, SX20, SX50 and SX200 can do this.

Equipment that cannot be converted will have to be replaced or have a special adaptor fitted to a trunk line.  In the second case the following applies:-

Installation and use of an Adaptor

Trunk circuit(s) on the telephone equipment are connected to an Analogue Terminal Equipment (ATA) which is connected to the internet. The calls go via the internet and and charges are generated against extension numbers.  The customer can then logon to the internet and pick up the charges on a per extension basis.  Ideal for a small hotel or similar environment with broadband connection.

Equipment and programming
The telephone equipment must have spare trunk capacity or cease some of the exchange lines already in use, as the ATA will take some of the traffic.  The ATA will connect to a IP network or directly to a router (Broadband unit).
The telephone equipment must be capable of sending account codes to line.  The Siemens Hicom 110, 120, 125 and 130 range can do this.

Pro's and cons

  • By reducing the exchange lines and using the internet - rental savings.
  • Save money by not replacing your telephone equipment with a new system and a call logger.
  • Must be on Broadband.
  • Real time billing available on line.
  • Must have a PC available to access the internet - any PC with network capability can do this.
  • The telephone equipment must have the capability to send defined extension (hotel rooms etc) calls to the ATA.  This is to ensure that all calls are logged.
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Last revised: November 30, 2018