Detailed description of Trunk Flash

Last Updated : Oct 30, 2012 |

With Trunk Flash, a user of a multifunction telephone or an attendant console can gain access to far-end customized services or central office (CO) customized services. To use Flash Trunk, the user presses the flash button or dials the Feature Access Code (FAC) for Trunk Flash.

CO customized services are electronic features, such as conference and transfer, that are accessed by a sequence of flash signal and dial signals from a Communication Manager telephone on an active trunk call. The Trunk Flash feature can help to reduce the number of trunk lines that are connected to the server that runs Communication Manager by performing:

  • Trunk-to-trunk call transfers at the far-end or the CO, which eliminates the use of a second trunk line for the duration of the call, and frees the original trunk line for the duration of the call.

  • A conference call with a second outside call party, which eliminates the need for a second trunk line for the duration of the call.

Note:

Some analog dual-tone multifrequency (DTMF) telephone sets that are used in Italy and the United Kingdom have a Flash button. When a user presses that Flash button, the button generates a rotary digit 1. When an analog telephone that is administered as a DTMF telephone, for example, as a 2500 or a 71nn-type telephone, transmits a rotary digit 1, the system processes the signal as a recall signal from the telephone set to Communication Manager.

A centralized attendant service (CAS) attendant who is connected to a release line trunk (RLT), the Flash button controls certain CAS features at the branch. For a user of a multifunction telephone or non-CAS attendant connected to a CO, foreign exchange (FX), or a Wide Area Communications Service (WATS) trunk, the flash controls certain features, such as add-on, at the connected CO.

Trunk Flash is unavailable on Personal Central Office Line (PCOL) groups.

The system supports the Trunk Flash signal for incoming, outgoing, or two-way call directions on selected two-wire analog or digital DS1 trunks, or tie trunks on DS1.

If the trunk group is a DS1 trunk in Italy, the Trunk Flash feature applies only to outgoing calls.

If the trunk is indirectly connected to the far-end or the CO that provides the customized services, use of the Trunk Flash signal can cause the far end or the CO to disconnect the call.

The system does not record Call Detail Recording (CDR) information for calls that a user makes with the Trunk Flash feature.