One that has bitten me: "ACKs come from an end node" Cellular carriers will ACK a packet destined for a device on their network before they have actually deli

One that has bitten me: "ACKs come from an end node" Cellular carriers will ACK a packet destined for a device on their network before they have actually delivered it if they have the device registered and are confident they can deliver the packet "soon." I have seen packets happily being ACKed that are destined for a device that I just powered down. About a minute later the carrier starts telling the truth, but now you have no idea what actually got through to your device.