UDP ports and firewalling

[kersing (Jac Kersing)]

@Epyon

But still strange that the gateway doesn’t initiate push_ack when at work

Push ack is the response from TTN, it looks like all return traffic is (still) being blocked by some firewall.

@arjanvanb

Instead, it seems it only changes targets ports for PULL_RESP when receiving a PULL_DATA message, not when receiving other packets such as an uplink or statistics

Confirmed: The PULL packets use one UDP ‘connection’ and the PUSH (data and statistics) use another. Both ‘connections’ have their own originating ports and the back-end replies to the port associated with the connection.