[AusNOG] Telstra Mobile NAT64 Gateway dropping UDP?

[Matthew H]

Hi,

We are developing a WebRTC mobile app that sets up a media session via Web
Socket and then sends the media via RTP over UDP. It's working on most
networks but we've had users report issues with the app when their iPhone
is connected to the Telstra Mobile network.

Unfortunately our network only supports IPv4, and after examining the
available logs it appears their iPhone only gets an IPv6 address. The Web
Socket communication is able to reach us so I assume a NAT64 gateway is in
use, but we don't see any RTP / UDP arrive at our network edge.

We found a couple of posts that suggest users have had similar issues with
UDP being dropped:

https://crowdsupport.telstra.com.au/t5/network-roaming/unable-to-stream-video-over-udp-on-ipv6-only-connection/td-p/933472
https://crowdsupport.telstra.com.au/t5/network-roaming/ios-and-ipv6/td-p/931449
https://crowdsupport.telstra.com.au/t5/apple-ios/nordvpn-won-t-connect-on-4g-ios/td-p/932511

Is anyone aware of Telstra's NAT64 gateway dropping UDP?

Thanks
Matthew
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ausnog.net/pipermail/ausnog/attachments/20220104/972628a0/attachment.htm>