LANCOM 1722 VoIP – LANCOM 1723 VoIP – LANCOM 1724 VoIP – LANCOM 1823 VoIP
Chapter 12: Configuring the ISDN and analog interfaces in detail
122
EN
12.2
Bus termination, life-line support and power supply
The hardware function modes of the ISDN interfaces are set by DIP switches
on the underside of the device.
Bus termination
is obligatory with an ISDN interface in NT mode.
Bus termination is generally deactivated for ISDN interfaces in TE mode.
If the LANCOM VoIP Router is the last device at a longer ISDN bus and this
itself is not terminated, it may be advantageous to activate the bus termi-
nation for an ISDN interface in TE mode.
Not including
LANCOM 1724
VoIP
If
life- line support
is activated, the interfaces ISDN 1 and ISDN 2 are
bridged if the device is unavailable due to a power outage or if the ISDN
2 interface is switched off (default: on). The life-line support is used when
the LANCOM 1722 VoIP is connected to an external ISDN line over a TE
interface with the simultaneous operation of ISDN terminal devices at the
internal ISDN connection of an NT interface. If bridged, the ISDN devices
can then use the external ISDN bus directly.
To activate life-line support, all four DIP switches (3 to 6) must be up; to
deactivate, all four DIP switches must be down.
Life-line support is to be deactivated when both ISDN interfaces are
to be operated in the same mode, i.e. as two TE or two NT interfaces.
The interfaces are not to be bridged in case of power failure when
being operated in this manner!
LANCOM 1722
VoIP and LANCOM
1724 VoIP only
The
ISDN power relay
means that the bus voltage of an external ISDN
bus at ISDN 1 is switched through to the terminal equipment connected
to ISDN 2 (LANCOM 1722 VoIP) and/or ISDN 3 (LANCOM 1724 VoIP). As
a consequence, ISDN equipment operated at the internal ISDN bus of the
LANCOM VoIP Router can be operated without its own power supply.
Be sure to deactivate the ISDN power relay if both ISDN interfaces are
to be operated in TE mode, such as when both ISDN interfaces are
connected to an ISDN NTBA, for example. A power relay in this situ-
ation would result in a short-circuit which would damage the device
and the ISDN NTBAs!
To activate the power relay, the corresponding DIP switches (7 and 8 on
the LANCOM 1722 VoIP, 5 and 6 on the LANCOM 1724 VoIP) must be up;
to deactivate, the DIP switches must be down.
