AT Commands Reference Manual - wireless netcontrol GmbH

Packet Data
Using the ATD* Command Set
Request packet data service 'D':
ATD*99***(CID)#
The CID (Context ID) includes the APN (defined by the AT+CGDCONT command) to which
you want to be connected. This depends on the ability of the SIM card to be attached to the
different networks.
The format ATD*99# may also be used. In this case, the H24 will first try to activate a non-empty
(predefined) CID. If the attempt fails, the H24 will try the next CID, and so on.
Note: When buffering the terminal message, data in the H24 (both inbound and outbound data),
the following apply:
• Turning off the H24 clears any buffered data.
• Removing power from the H24 clears any buffered data.
• Whenever the terminal drops the PPP connection with the H24, via LCP terminate, the
buffered data is cleared.
• Whenever the H24 drops the PPP connection with the terminal, with LCP terminate,
the buffered data is cleared. LCP termination triggers the termination of the data in the
H24 buffer.
• Whenever the H24 drops the PPP connection with the terminal, without an LCP
terminate, the buffered data is cleared. Dropping the DTR also clears the buffer.
• When the network sends a deactivation message or a detached message, the H24 buffer
is cleared.
• When the H24 transfers data in the uplink and packet data coverage is lost, the data
may flow-off. If the mobile has lost coverage and is unable to send the packets from
the terminal to the network, the buffers will continue to store the packets until the
buffers are full. The terminal will then be flowed off and the packets will be stored until
they can be sent to the packet data network.
• The amount of time that takes before the user is notified is specified in the T3312 timer
that is located in the mobile side. The default delay time of T3312 is 54 minutes, as per
the GSM 0408 specification. After 54 minutes, the H24 deactivates the PDP session.
4-18 H24 - AT Commands Reference Manual April 15, 2010