> why would bringing an interface up interfere? We are doing this right > now. Just the IP assignment is done by ConnMan, but the interface > up/down status is controlled by oFono or even BlueZ in case of > Bluetooth. Logically whoever sets the IP parameters should bring the interface administratively up. This is layer 3. oFono does layer 2. It should either create/remove the interface and/or play with the dormant and/or carrier flags.