RTS SIP-ISDN, Hardware & Software Manual, Page: 35 / 102

35
ISDN Parameters
FIG. 18 LINE INTERFACE ISDN
Prefix Number
• Under Length of Internal Telephone Numbers you indicate the length of your
internal telephone numbers. In this way, the prefix number is dialled automatically, if
the length of the calling number is bigger than the length indicated here. If you do not
want to use this functionality, or if you use the system with a main connection, please
enter a
0 into the respective field.
Examples: Length of internal telephone numbers: 3
Calling number entered: 130
It is dialled: 130
Length of internal calling numbers: 3
Calling number entered: 5271130
It is dialled:
0 5271130
• Under External Prefix Number you enter the external prefix number which you
must dial to get an outside line. In most cases it is 0.
• Some PABXs transmit the calling number with prefix number to the system. If you
want to transfer the displayed calling number without the prefix number directly into
the telephone book, you can enable the function
Skip prefix number on inco-
ming call
.
NOTE
The following settings are only necessary if the system is used with a PABX.
ATTENTION You must enter the external prefix number at any case if you operate the system with
a PABX since only in this case the system waits for a dial tone. Without an external
prefix number, the calling number is transmitted too fast and the connection cannot
be established.
!