34
the modem cannot enable internet connection using the operating SIM card within the specified time inter-
val;
it is time to switch to the primary SIM card.
When enabling
Schedule
option, operation of each SIM card can be scheduled separately. The modem op-
eration with SIM cards is set up in the tab
Settings → Advanced → SIM
of the ATM Control utility.
4.8. Working with the Server
The client modem provides transparent data communication between the serve and an external device, con-
nected to the modem, in the network over TCP/IP. To set up connection, specify an IP address and the server
port in the modem settings (the tab
Settings → Basic
in the ATM Control utility).
Either one or two IP ports can be arranged to access the modems in the backup mode on one server. When
using the second IP address (for example, from other provider), the access to the server is available when it is
not provided for the first address. Taking this into account, the following combinations with maximum available
use of backup:
one server
– with two IP ports (two IP ports for the modems in overall count);
two servers
– with two IP ports (four IP ports for the modems in overall count);
three servers
– one server with two IP ports and two servers with one IP port (four IP ports for the mo-
dems in overall count);
four servers
– each has one IP port (four IP ports for the modems in overall count);
If you intend to use backup server(s), enable the use of these servers in the modem settings and specify
their IP address and port. The modem switches to the backup server (or to other IP address of the same serv-
er) if connection to the first server is lost (or or to the first IP address of the same server) or on a signal from the
modem pins. The flow diagram (see Fig. 4.1)
illustrates the procedure of selecting a production server when
operating with two servers, one of which is a backup one.
