h721 + QUECTEL RM502Q-AE - Internal NAT?

[Dubious Human]

Configuration:

• T-Mobile Home Internet SIM
• Quectel RM502Q-AE pretending to be the original T-Mobile Askey 4G gateway
• h721 router with Goldenorb

Issue:

When using the sim in the original Askey gateway, I have no issues with gaming consoles (NAT type B on Switch, Type 2 on PS5) for multiplayer games, and my TP-Link Kasa smart plugs are accessible from outside the home network.

When I plug the SIM into the h721 I get a great, solid, fast connection, but my NAT type changes to F on the Switch, Type 3 on the PS5 and the smart plugs change to local control only. This is using the fbb.home APN.

It's acting in a similar fashion to having a router behind the original Askey gateway. Trying to figure out if there is a configuration I'm missing that's adding another layer to the network by default that would block network traversal.

Any insight is appreciated.

[Didneywhorl]

I think the original gateway is allowing some kind of passthrough maybe, and the openWRT firmware on the H721 maybe is not? Hard to say. I wouldn't think it would be adding an additional routing layer other than it's own.

[Dubious Human]

Honestly that's what I'm leaning towards. I've been a bit busy the last few days and haven't dug into it anymore. This weekend I'll get back at it.

Need to check and see if I'm on the most recent router firmware and continue to plug away.