Degraded China network performance Wednesday 27th July 2022 17:20:00


We are currently seeing degraded network performance to China using our AS4837 route, this is caused by a cut in the APG submarine fiber cable AS4837 uses.

Degraded performance may continue until this fiber cut is fixed.

China Unicom has said the APG Marine cable S3 has been repaired as of 06:45 UTC, this means all submarine cables are now back online. We're monitoring the network, let us know if you see any issues.

China Unicom has confirmed that the APG Marine cable S3 repair is scheduled to start on 1st September and is expected to be completed on 8th September. We believe that this submarine cable carries a lot of capacity so hopefully significant improvements will be seen when it's back online.

One of the offline submarine cables has been repaired but at least one, including the APG Marine cable S3, is still offline with no estimated restoration date, we believe this submarine cable being offline is responsible for most of the congestion. We'll update when we receive an estimated restoration date.

The submarine cable that was due to be fixed on 20th August has been rescheduled to 23rd August.

We've been informed that one of the currently offline submarine fiber cables is due to be fixed on 20th August but there is still one other offline with no estimated fix date so performance may still not improve to previous performance levels.

Throughput at peak time has dropped to very low levels, less than 5Mb/s multithreaded. Ceranetworks has confirmed they're seeing significantly lower traffic levels meaning the fault is still within China Unicom's network.