User Manual

SARA-R4/N4 series-AT Commands Manual
UBX-17003787 - R11
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13Packet switched data services
Page 131 of 308
If the command is accepted and the preliminary PS procedures have succeeded, the "CONNECT" intermediate
result code is returned, the MT enters the V.25ter online data state and the PPP L2 protocol between the MT
and the DTE is started.
The data session is terminated by one of the following events:
• sending ~+++.
• via a DTR transition from ON to OFF.
• sending an LCP Terminate Request.
If used with <cid>= 100, this command can enable the local dial-up, that establishes a PPP communication
between the DTE and the module through a serial interface (UART, MUX, or CDC-ACM). In this case an active
PDP context is not needed since the DTE is assigned a private IP address.
13.7.2Local dial-up
The local dial-up feature is enabled by performing a dial-up on <cid>= 100. It establishes a PPP communication
between the DTE and the module through a serial interface (UART, MUX, or CDC-ACM). An IP link is created
by assigning private IP addresses to the endpoints. An active PDP context is not needed. The IP traffic is
automatically routed by the module, thus allowing the DTE to communicate with:
• the internet through an active PDP context (at least one PDP context/EPS bearer is needed for the IP
connectivity). By default, the first PDP context activated is used to convey the data;
• a device connected to the Virtual Ethernet over USB (RNDIS/CDC-ECM);
• devices (STA) connected to the Wi-Fi access point (AP) of the cellular module (see Wi-Fi section).
The feature has been studied to work in router mode.
In general no defined / no active context is required to use local dial-up. The local dial-up is in any case able to
communicate with the interfaces connected to the module IP stack, as for example RNDIS and Wi-Fi interfaces.
The local dial-up feature does not support the OnLine Command Mode (OLCM). Furthermore the DTR ON to
OFF transition and the ~+++ cannot be used to terminate the local dial-up (the procedure described in ~+++
behavior in PSD &D is not applicable).
The PIN insertion is not mandatory for the local dial-up feature.
13.7.3Syntax
Type Syntax Response Example
Set ATD[<dialing_type_char>]*<dialing_
number>[*[<address>][*[<L2P>]
[*[<cid>]]]]#
CONNECT
(data transfer starts)
ATD*99***1#
CONNECT
13.7.4Defined values
Parameter Type Description
<dialing_type_char> String Optional (legacy) "T" or "P" character indicating the tone dialing or pulse dialing
respectively
<dialing_number> Number List all the supported values
<address> - Ignored
<L2P> String Layer 2 protocol to be used between the DTE and MT; allowed values:
• "PPP" (default value)
• "M-HEX"
• "M-RAW_IP"
• "M-OPT-PPP"
The application on the remote side must support the selected protocol as well.
<cid> Number See <cid>
13.7.5Notes
• Dial up with PAP/CHAP authentication is not supported on an already active PDP context that was
activated without authentication.
• The context identifier <cid> is mapped to 1 if not specified.
• The GPRS dial-up command maps to AT+CGDATA="PPP",<cid>.