coM.sat ISDN Basic
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16/01/09 23 coMsat ISDN Basic Manual V2.7.doc
Note Protection Mark according to DIN 34!
If the telephone system additionally has a fixed network connection and it reports too
many errors (frame slips, bit slips), a synchronisation may be necessary. These types
of errors are unimportant for voice communications. However, in mostly larger TC
systems with more elaborate trouble shooting procedures, problems can occur during
operation that can cause this “faulty“ port being switched off. This can be avoided by
synchronisation. In this case, the synchronisation input of the coM.sat ISDN Basic is
connected directly with the system port (fixed network). The synchronisation clock is
then derived from this signal.
If an optional add-on board is employed, it is possible to derive the synchronization
clock from the NT port rather than the synchronization port. The parameter field
labelled "Sync from" defines which port is used for synchronization. If the
synchronization on the NT port is selected, the connected TE device must use a
clock on that port synchronized to another source. Note: Since the presence of the
add-on board is not detected, the parameter field is always enabled in NT mode even
if the add-on board is not employed. See also chapters 4.1 and 4.3.
The PBX number entry also depends on the telephone system. Some systems do not
require an entry here. As the entry of Multiple Subscriber Numbers isn't necessary in
NT-mode, their respective boxes are inactive.
TE-Mode operation
If the coM.sat ISDN Basic is to be used in TE-mode, that is like a simple extension,
then click the corresponding radio button for layer 3. Layers 2 and 1 will automatically
be set to TE-mode. In this mode (operating on the telephone system's internal S0
bus) there is usually a point-to-multipoint connection. Therefore the line type is
automatically set to this type of connection.
It is also often necessary to identify those extensions (Multiple Subscriber Numbers 1
and 2) via which the device is identified by the telephone system. Both GSM
channels may be addressable by the same MSN if supported by the telephone
system. If at least one MSN is empty, the device accepts any called party number
and uses that number for the outgoing call. This means that the MSN is dialled via
GSM, which is usually not desired. This function is useful if there is a diversion or VIP
number programmed for each possible MSN, so that the MSN is converted into a
valid GSM number.
If used in TE-mode, as terminal equipment, no synchronisation is necessary.
Router operation
If the coM.sat ISDN Basic shall be able to route calls from one ISDN port to the
other, then activate the box labelled “Allow routing from one ISDN port to the
other”. Layers 3, 2 and 1 will automatically be set to NT-mode because this reflects
the setting of the ISDN port labelled “NT”. The line type automatically changes to
point-to-point connection. The mode of layers 2 and 1 and the line type may be
changed subsequently, but layer 3 of the NT port remains in NT mode, layers 3 to 1
of the TE port always operate in TE mode, and the line type setting applies to both
ports.
The PBX number entry also depends on the telephone system. Some systems do not
require an entry here. As the entry of Multiple Subscriber Numbers isn't necessary in
router mode, their respective boxes are inactive.