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Laird Technologies
BTM510/511
Bluetooth
®
Multimedia Module
8. DUN (Dial-Up Networking Profile)
The Dial-up networking profile (DUN,[6]) defines protocols and procedures for the dial-up networking
use case. Scenarios are the usage of a wireless modem or a cellular phone for dial–up Internet
connections or the usage of a wireless modem or cellular phone to receive data calls by a PC.
There are two roles defined:
1.) Gateway (GW)-This device provides access to the public network (e.g., cellular phone or modem),
and role is not supported on BTM.
2.) Data Terminal (DT)-This device uses the dial-up services of the Gateway (e.g., PC), and is
supported on BTM.
In order to map these roles to the conventional modem structure, the Gateway is referred to as Data
Circuit Endpoint (DCE), and the Data Terminal is referred to as Data Terminal Endpoint (DTE).
A BTM module is required to be controlled by a host processor using AT commands (hosted operation
mode). BTM DUN implementation supports DT role only.
The DUN profile belongs to the group of serial stream oriented profiles (SSO). The appropriate
implications and restrictions are described on page 24.
An AT command beginning with AT+DU... indicates affiliation to the DUN profile.
Service
Support in DT
Support in GW
Specification
BTM
Specification
BTM
1.
Data call without audio feedback
M
Yes
M
No
2.
Data call with audio feedback
O
No
O
No
3.
Fax services without audio feedback
N/A
No
N/A
No
4.
Fax services with audio feedback
N/A
No
N/A
No
5.
Voice call
N/A
No
N/A
No
M: mandatory
O: optional
N/A: not applicable
8.1 Profile Activation
DUN profile is activated by setting flag 0x04 in S102 plus “AT&W” plus “ATZ“.
8.2 Initiate DUN Connection
AT+DUD<bd_addr
hex
>
Initiate ACL connection to remote device with <bd_addr
hex
>. The remote device must support the
DUN profile (HSP).
Response: <cr,lf>CONNECT 123456789012,1103,><cr,lf>
Or:
<cr,lf>NO CARRIER<cr,lf>
Or:
<cr,lf>ERROR 59<cr,lf>
Or:
<cr,lf>ERROR 63<cr,lf>
Or:
<cr,lf> ERROR 65<cr,lf>
After an DUN connection has been established, the module changes its mode to the mode
defined by S Register 531. The recommended value is S531=0 for a DUN connection (=default).
Before initiating a DUN connection, S507 must be set to 2 (ats507=2). This will cause the module
to escape from connected mode to command mode by toggling DSR line only. An escape
sequence of “^^^” is not compliant with the DUN specification. S507=2 also configures
the module for high data throughput.
Once the Bluetooth connection is established all data arriving at the UART is transferred to the
gateway, hence any AT commands will be transferred directly to the gateway. Now the host can
e.g. dial in to the internet provider by “ATD123456” as if directly connected to a serial modem.
AT COMMAND SET
REFERENCE