ISDN (Integrated Services Digital Network) is a well-established and dependable technology that offers a digital solution for customers who are looking to upgrade from a basic phone line but may not be fully prepared for an IP-based system.
Referred to as Telstra ISDN2, ISDN10/20/30, or Optus Multiline, ISDN enables multiple calls to be made simultaneously on a single phone number. Additionally, each staff member can have their own individual phone number, facilitating multiple inbound and outbound calls.
Unilakes recommend your customers transition to the more advanced SIP based solutions, however, in certain circumstances an ISDN product may be more suitable.