User manual

6.5.9. Data Connection Problems
GSM data transmission is different from analog CO line data transmission: it is necessary
to specify in advance whether the case will be voice, data or fax connection. With the
connection once established, the connection mode cannot be changed. Therefore, the
calling party should select the required connection before establishing it and this
information should get to the target GSM network operator through all networks involved.
Experience from other countries and operators show that this is quite impossible in some
cases and not fully reliable in other cases. For an overview of remote supervision options
with/without call-back see the table below.
Service Client’s GSM Gateway No Call-back With Call-back
GSM
gateway
One and the same GSM
operator
No problems
No problems, you need not
select the data number for call-
back.
GSM
gateway
Another GSM operator,
SIM
has no special data
number.
No guarantee; it works if both
operators are able to establish
data connection between each
other, in the direction from
service to client.
No problems if the call-back
data number is used.
GSM
gateway
Another GSM operator,
SIM
has a special data
number.
No problems if the called GSM
gateway data number is used.
No problems if the call-back
data number is used.
ISDN
modem
Any GSM operator
No guarantee; it works only if
both operators are able to
establish data connection
between each other, in the
direction from service to client.
No guarantee; it works only if
both operators are able to
establish data connection
between each other, in the
direction from client to service.
Analog
modem *)
Any GSM operator, SIM
has a data number.
No problems if the called GSM
gateway data number is used.
No problems
Analog
modem *)
Any GSM operator, SIM
has no data number.
Not applicable No problems
*) IMPORTANT! The analog modem must be connected to a CLIP-sending PBX.
Table – SIM Card Identification Options for Outgoing Calls:
Voice number Data number Number used for outgoing call identification:
YES NO voice number
YES YES voice number
NO YES data number
Note: The SIM card can have another number for fax calls, which is no important for remote
supervision.
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