I see lots of mentions of this option on Android sites, including Android.StackExchange.com, but I don't see any technical exploitation for what it does. What does this option actually do?
Tells telephony manager dial up networking emulation not required, not sure if thats actually required if you use net.tethering.noprovisioning=true in build.prop you can see the telephony and tethering code in the links below
Not exactly sure what it does, but a lot of people seem tho think this in
adb shell gets them free tethering.
su settings put global tether_dun_required 0 exit