Telstra outage: The night a network decided the year was 2006
5 points by fanf
5 points by fanf
The idea that TDD systems rely on NTP for synchronization seems laughable - no way it would be accurate enough, surely. PTP maybe?
https://www.telstra.com.au/content/dam/tcom/dynamic-media-projects/exchange/TAPFindingsforTelstraOutage.pdf seems to imply the problem was some control plane stuff fell over due to inaccurate time (certs maybe?):
Starting at around 4am July 8th, 2026, when Mobility Management Entity (MME) instances began to reset, end users of Telstra’s network experienced varying levels of impact in their ability to communicate on the network, however not all users were affected. These impacts precluded some users from being able to make/receive voice calls [..]
Also:
The IP Multimedia Subsystem (IMS) Core was significantly impacted. It is responsible for signalling management between the user and the services they are trying to use. Until the correct network date was restored, information for approximately 30,000 IP address prefixes were incrementally corrupted (wriLen with the wrong date) by the Diameter Signalling Controller (DSC) in such a way that access attempts using those addresses were blocked from using the network
PTP maybe?
Seems to be the usual from what I found on the Internet. Towers can also have individual GPS modules, since it's accurate enough. The accuracy required is around 1 µs time, and 50 PPB frequency.
(Also, it becoming 2006 wouldn't matter for TDD, all that matters is they share some "origin" even if it's 20 years incorrect.)