Lancom Systems 1723 VoIP, annex B (ADSL over ISDN) LS61359 User Manual

The business VoIP gateway LANCOM 1723 VoIP belongs to the LANCOM VoIP portfolio and offers interfaces for SIP and ISDN terminal equipment along with 

additional connectors for analog telephony. 

Typical application scenarios include single sites or branch offices with up to 10 telephony subscribers using ISDN and/or analog terminal equipment—such as

DECT telephones or a fax machine—which is to be integrated into VoIP communications. Interesting for overseas subsidiaries without ISDN, the LANCOM 1723

VoIP allows existing analog telephone equipment to be used for VoIP, so providing investment protection and cost savings.

Telephone calls can be automatically directed over existing VPN connections between company sites. Not only are these calls secured from interception; by using

flatrate connections, there are no additional call costs, either. 

Small and mid-sized companies can even save themselves complete PBXs by equipping new installations with a LANCOM VoIP gateway instead. 

LANCOM opens up a cost-effective migration path between technologies of the “old and new world” because existing ISDN and analog telephones and PBXs can

be integrated and operated side by side with SIP terminal equipment.

An internal ISDN and two analog connectors provide four simultaneous voice channels for optional combination with an analog or ISDN exchange line. For 

example, this allows an existing ISDN PBX to be equipped with SIP, enhanced with analog and SIP terminal equipment, and additionally to be connected to an 

upstream VoIP PBX over VPN. Subscribers can simultaneously make calls via ISDN telephones, analog phones, SIP equipment or softphones to other SIP or POTS

subscribers, both internally and externally. The transition between analog, ISDN and SIP is automatic and invisible to the user.

With life-line support either between the internal and external ISDN ports or from analog to analog, telephony remains possible even when the router is switched

off. SIP connections with redundancy and high reliability are ensured by backup over ISDN or analog exchange line, load balancing, and VRRP in combination with

an Ethernet port as an additional WAN interface. This ensures that telephony is just as reliable as ever, even with Voice over IP.