Beryl AX USB iPhone tethering.. mangling TTL doesn't avoid hotspot data?

Technical Support for Routers
1

Just looking for a confirmation from someone more knowledgeable than I... can someone confirm that tethering an iPhone (16 Pro, doubt that matters) via USB to a Beryl AX and mangling the TTL/HL to 65 does NOT avoid the data being counted as "hotspot data" on T-Mobile? It doesn't appear to matter in my testing. Is this because the iPhone is using a hardcoded APN when "personal hotspot" is enabled? Or is there something else in play here?

For reference sake here are the rules I'm using to mangle TTL/HL and I can confirm that packets are hitting the v4 rules at least..

iptables -t mangle -I POSTROUTING 1 -o eth2 -j TTL --ttl-set 65
ip6tables -t mangle -I POSTROUTING 1 -o eth2 -j HL --hl-set 65

Chain POSTROUTING (policy ACCEPT 10738 packets, 6604K bytes)
pkts bytes target prot opt in out source destination
58663 6309K TTL all -- * eth2 0.0.0.0/0 0.0.0.0/0 TTL set to 65

2

The latest firmware of MT3000 can set TTL in GL GUI tethering.
Please try to set it directly in the GUI.

image
image1025×413 11.6 KB

4

It's been my experience that some cellular carriers are now able to detect hotspot (tethering) data even when the TTL/HL has been mangled. I have however found that combining the mangle with a VPN does allow the hotspot/tether to go undetected when using Visible's network. I have not confirmed on T-Mobile.

5

Ya it doesn't have any effect when USB tethering an iPhone 16 Pro; at least not in terms of bypassing the data being counted as "hotspot" data.

6

This may require capture the packets to check the reason why tethering can be detected.

In other words, some operators have restriction from the SIM subscription package and do not allow data sharing at all.