Call transfer is made using a transfer feature key (TRN) which is predefined for UNIStim and 39XX endpoints as a soft key at a fixed position, but may be disabled (removing transfer capability). For digital 200X endpoints the button may be defined at an unfixed programmable position.

The Transfer soft key is available only on the phone screen during an active call. For digital 200X stations, the button is always present, but it does not function unless there is a call. In practice, it is present, but behaves as though it was not there until an active call exists on the station.

The active call may be on any line appearance (both the user’s extension and any auxiliary or shared numbers programmed on the station). On activation of the transfer key, the active call is put on hold, and the user receives a new dial tone when it is pressed. After the far-end is reached, the user can either complete the transfer (blind) or wait until the far-end answers the call and then complete the transfer (consultative). The transfer completion is done by pressing the Transfer key again.

The transfer call is made on behalf of an active DN key. For example, phone A has a primary DN 2000 on key 0, DN 2001 on key 1. When there is an active call with key 1, the user initiates a transfer to another set B. Set B rings and displays DN 2001 as the caller number, not the primary DN of set A.

A transfer using the conference function is also available. The user creates a conference and hangs up.

Call transfer is made by using a hook flash and subsequent operations.

The analog station requires the transfer class-of-service to be permitted because there is no button to program with the transfer function. The absence of the button does not indicate that transfer is denied.

The transfer service automatically allows three-party conference. On CS 1000, it is necessary to add a class-of-service to permit a six-party conference.

The Transfer function is available only during an active call. The call may be an existing conference, when six-party conferencing is allowed.

When the user does a switch hook flash, the active call, including conferences that are below the maximum size for an ad hoc conference, is put on hold. The user receives a new dial tone and can dial the transfer target number.

After the far-end is reached, the user can either complete the transfer (blind) or wait until the far-end answers the call, and then complete the transfer (consultative). The transfer completion is done by hanging up.

Transfer can be cancelled by doing the switch hook flash while the call is ringing.

The corresponding transfer operation for Communication Manager is the “Pull Transfer”. The Communication Manager documentation description begins as follows: With Pull Transfer, either the transferring party or the transferred-to party can press the Transfer button to complete the transfer operation.

What button is used depends on the endpoint. It may be a soft key, or a fixed button. However, from the user experience, the mode used by the CS 1000 user has an almost exact match in Communication Manager. Note, though, that additional supplementary options vary; a large overlap exists, but some elements are not identical.

It should be noted that the H.323 endpoints on Communication Manager have an even closer correlation than the 96x1 and J-series SIP stations. As with the CS 1000, the transfer key “hides” a virtual call appearance underneath the transfer button. Pressing the button simultaneously requests the “spare” call appearance and requests the transfer service. SIP endpoints may do this if configured to do so. However, the call may also be put on hold, a new line appearance selected, and the transfer initiated at that point.