User Manual
11
z
If you have two VoIP numbers, you can connect two telephones to the PHONE/FAX and
PHONE interfaces respectively. Only the PHONE/FAX interface provides the emergent
public switched telephone network (PSTN) function. When the DSL network cannot
work, the HG556a chooses the PHONE/FAX interface automatically to provide the PSTN
function.
z
If you have only one VoIP number, when you are using the VoIP function on one of the
PHONE/FAX and PHONE interfaces, the other interface cannot provide the VoIP
function. The functions of these two interfaces are determined by the configuration of
your Internet service provider (ISP).
Note for the PSTN function
:
If you have no VoIP number and use only the PSTN function, then
connect the telephone to the PHONE/FAX interface.