User manual

3.1.6. Connection Making and Establishing

In this moment, GSM gateway sends whole received number (or a number changed by

“take away” and “append” parameters) to the GSM network. Next, GSM network is

making a connection, and it takes typically 8 seconds. During this time, the subscriber

hears a special "call progress" tone (differs by GSM gateway model and version of

software). Next, the subscriber usually hears the ringing tone

another signal transmitted by the GSM network. The connection, however, is not

established and paid for until the called party answers the phone. The GSM network

signals this moment and the GSM Gateway can pass the information to the PBX. If this

type of signalling is used (exceptionally), the calling party can hear a click in the

earphone.

3.1.7. The Call

The call may be terminated forcibly if the GSM signal gets lost, for example, or in similar

situations.

During the call, GSM gateway keeps PSTN line off-hook. This is important because GSM

gateway is not able to serve incoming call from PSTN, till PBX line is busy by outgoing

GSM call. If somebody will call to you (via PSTN line), he or she will get busy tone from

public exchange.

3.1.8. Tariff pulses

During outgoing call to GSM, the GSM Gateway can transmit pseudo-tariff pulses,

according to the Call Sorting Table.

ATTENTION! If filled wrong, it may cause that these pulses will not be transmitted, or will

not show a true price of the call.

3.1.9. Connection Termination (End)

If the caller is the first to hang up, the GSM Gateway registers the on-hook immediately

(the current flow stops) and terminates the connection. If the called party is the first to

hang up, the GSM Gateway gets the information from the GSM network and terminates

the connection. The GSM Gateway can pass the information to the PBX. The calling

party gets the busy tone

(or another type depending on the set-up).

The time of call may be limited by parameter 158. 30 sec before this limit, GSM gateway

sends a warning tone. Last 10 sec a short beep repeats each second. A call interruption

follows, optionally busy tone and Power Down.

Note: With some calls, the called party‘s on-hook information is considerably delayed by

GSM network (30s, e.g.). The subscriber usually registers the on-hook earlier, hangs up,

and the GSM Gateway terminates the connection immediately.

3.1.10. Subscriber’s Disconnection (Power Down)

If a subscriber blocks the GSM Gateway by seizing the line without dialling a number, or

fails to hang up after the call, he or she will get the busy tone

first and

then is disconnected (Power Down status).

3.2. Outgoing Call to PSTN

Till call routing, GSM gateway behaviour is the same as during GSM call. See chapter 3.1.1 to

3.1.4 for its description.