is there a way or strategy to let the gateways work semi independent of the network server. Like pre authenticating certain ranges of IDs and later when the network is more reliable or up, the real packet filtering is done.
I have a case were sometimes the gateways are down due instable network conditions like celullar and satellite communication.
Can I achieve this with the join filters and a quality of service of 1
One option is to have a network server running on each gateway, which would support your entire approach, but may have a high maintenance burden. Another option is to have device join/rejoin mechanics support this type of network connectivity, which is not uncommon. The gateway bridge can be configured to queue messages while offline, so you really only need to worry about getting that initial join through.