I am running the modemDemo sample application on a WP710x, using Developer Studio to display debug messages. When I sent the TestDataConnectionV4 SMS command to the application, it answered that it had failed to connect to sierrawireless.com.
After a rapid investigation, I discovered that once the data session is opened, the rmnet0 device is created. And routing table (as returned by ip route show) is:
which means that all connection requests targeting networks other than 10.193.224.0/24 will be routed over eth0, while they should be routed over rmnet0. To be sure, I modified the routing table:
(10.141.236.53 is the gateway address returned by the answer to the Netinfo SMS command).
And this time, the TestDataConnectionV4 worked perfectly.
Reading Modem Data Control section of Legato documentation, I didn’t find any way to specify the network interface to use, from an application. What would be the best way to do this?