CopiaFacts allows an inbound or outbound call (which will be referred to as CallA) to be connected to an outbound call (CallB) initiated by means of a $type transfer infobox.  The only hardware types currently supported for this feature  are Dialogic, where the calls are connected "over the SC-Bus", and Dialogic Diva ot TE systems where the calls are connected as a "Line Interconnect".  Copia VoIP ports are also supported in the same manner as Diva lines.

This operation is also known as a 'hairpin' transfer.

Default operation

A hairpin transfer is initiated by specifying a linegroup parameter on the $dial_cmd which initiates CallB.  Without this parameter the transfer is assumed to be a hook-flash or digital transfer and is dialed on the same line as CallA.

CallA does not hear the progress of the transfer.

When CallB is connected, Standard Voice Prompt 88 is played on this call to announce the transfer.  After this, the two calls are linked.

The call proceeds until either party hangs up.  If CallA hangs up first, Standard Voice Prompt 90 is played on CallB.  If CallB hangs up first, CallA is hung up without playing any message.

There are many possible customizations for hairpin transfers, the most important of which are described below.

Custom Announcement to CallB

For specific tasks, you can override Standard Voice Prompt 88 by specifying the full pathname of a voice message in  control variable LINK_INTRO in CallA prior to the transfer.  This message precedes the connection but gives no ability to cancel the link other than hanging up the call.

For links on Diva, TE Systems or Copia VoIP calls, variables containing voice file pathnames can contain up to eight pathnames, separated by +, for files to be concatenated.

Recording the Connected Call

Use either LINK_RECORD or LINK_DTMF_RECORD to specify a pathname for a recording file.  The latter variable requires the first $allow_interrupt break combination to be keyed before the recording starts.

Limiting Connect Time

You can use the $record_limit command to specify a maximum time for the linked call.  When this is exceeded, the link is broken and Standard Voice Prompt 89 is played on CallB.  This may be overridden using the variable LINK_WRAP_T.

Detecting DTMF keys

You can use the $allow_interrupt command to specify whether DTMF keys are to interrupt the link, when detected on each half of the call. When the link is broken for this reason, Standard Voice Prompt 91 is played on CallB.  This may be overridden by using the variable LINK_WRAP_D.