DLINK ASTERISK BASED IP PBX (PRIVATE TELEPHONE NETWORK), BUILT-IN EXPANSION MODULE (8010)
DLINK ASTERISK BASED IP PBX (PRIVATE TELEPHONE NETWORK), UP TO 30 USERS (10 CONCURRENT CALLS) BUILT-IN 2FXO PORTS
DLINK ASTERISK EXPANSION MODULE FXO 8-PORT FOR DVX-8000/DVX-9000, INCLUDING ONE TIME LICENSE ACTIVATION FEES