In a nutshell, I recently upgraded my firmware to 3.0.0.4.380_3281 from 3.0.0.4.378_9212 and now I am unable to receive inbound calls on my SIP softphone.
I upgraded because of some odd-looking activity in my logs (people trying to login remotely), and after seeing the change log for the current version I thought it was time to upgrade.
In 378_9212, I had WAN > NAT Passthrough > SIP Passthrough disabled - everything worked fine
In 380_3281 if I use the same setting, my phone won't...
DSL-AC68U - Latest Official Firmware and SIP Problems
I upgraded because of some odd-looking activity in my logs (people trying to login remotely), and after seeing the change log for the current version I thought it was time to upgrade.
In 378_9212, I had WAN > NAT Passthrough > SIP Passthrough disabled - everything worked fine
In 380_3281 if I use the same setting, my phone won't...
DSL-AC68U - Latest Official Firmware and SIP Problems