The function is available in some telephone networks and it allows
receiving the other call at the moment of the actual conversation by the method
of setting the active call in the waiting mode or cancellation. This will let
not to miss an important call and to agree upon time when it will be possible
to call back.
Citel PBXgateways are installed at the central PBX location, and EXTenders are deployed at branch offices, call centers, or at home offices over managed IP connections, DSL, cable, or analog circuits