The LANCOM 1784VA features four ISDN interfaces (2x NT and 2x TE/NT). This allows existing ISDN PBX systems, which were previously operated with up to four system or multi-device ISDN connections on the telephone network, to be connected to the new All-IP world via the router. This simple and cost-effective migration solution enables the continued use of existing ISDN telecommunication components even after the transition of Deutsche Telekom to All-IP. The router supports operation with individual SIP accesses as well as the new SIP trunk connections that replicate the former ISDN system connection.

The integrated LANCOM VCM (Voice Call Manager) allows for flexible management of telephone lines and phone numbers. This enables the simultaneous operation of ISDN end devices or PBX systems alongside new VoIP end devices and telephone systems. In addition to the ISDN participants, up to 10 VoIP participants can be registered per router by default.

The LANCOM VoIP +10 option allows for the registration of an additional 10 internal VoIP participants with their own phone numbers. Thanks to the additive licensing model, up to 40 VoIP phone numbers can be assigned. This allows for flexible expansion of the telecommunications infrastructure and a gradual transition from ISDN to VoIP telephony.