Internet traffic between Australia and Singapore has been going the long way since Friday afternoon, when Vocus's Australia Singapore Cable broke in Indonesian waters and took out the second of the two subsea cables that run directly from Perth to Singapore. The first, INDIGO West, has been out since 8 August with a fault off Perth. Vocus has not given a repair date and its next scheduled update is Friday morning.
The break means a request from a computer in Melbourne to a server in Singapore now typically crosses to the east coast and then the Pacific, reaching Singapore by way of Japan or the United States, before the answer comes back the same way. Global Secure Layer, a wholesale provider that carries traffic for Australian retail ISPs, warned its customers at 4.49pm on Friday that the detour "will result in higher latency between Australia and Singapore" because INDIGO West was already offline. For anyone whose game server, trading platform or corporate network sits in Singapore, that shows up as delay.
Vocus's incident record dates the start of the fault to 6.12am AEST on Friday, 4 September. Global Secure Layer's monitoring saw the cable flap at 1.50pm and go hard down at 4.19pm, and Vocus opened its incident ticket at 4.13pm. Its first public notice, at 6.26pm, said: "Vocus has detected a fault condition on the Australia Singapore Cable system impacting traffic between Perth and Singapore. Wavelength and Ethernet services are unavailable, and internet traffic has been rerouted via other paths. The fault appears to be a subsea cable fault in Indonesian waters." By Saturday morning the company had narrowed the location to the stretch between Anyer, on the west coast of Java, and Singapore. Overnight on Saturday it ran optical tests from the Perth cable landing station to measure the exact distance to the break, which cut Christmas Island's services off the cable for the six hours of testing.
On Monday morning Vocus said repair planning was under way with its marine partner, including "confirmation of the required spare materials, and coordination of the necessary permits and regulatory approvals". The company classifies the incident as "Minor - International" on its outage board, records no impact on emergency calls, and lists the cause as a "suspected shunt fault". A shunt fault is a breach of the cable's insulation that shorts its power feed to seawater. Vocus has not said what caused it and the next update is due by 10am AEST on Friday, 11 September.
The Australia Singapore Cable runs 4,600 kilometres from Perth to Singapore with branches to Christmas Island and Anyer. Vocus designed, built and solely operates it. The company's own figures put its capacity at up to 60 terabits per second over four fibre pairs, and it entered service in September 2018. Until Friday it was the route that retail providers had fallen back on after INDIGO West failed.
INDIGO West, built by a consortium that included Telstra, Singtel, Google, AARNet and Indosat and in service since 2019, went hard down on 8 August with a shunt fault about 48 kilometres off Perth, according to updates its resellers published. A repair ship has been on site since 2 September and the work is scheduled to run to 11 September, and the same reseller notices list further shunt works at the Singapore end of the cable that have been pushed back to 2 October. Its sister system, INDIGO Central between Perth and Sydney, has its own shunt fault off Perth booked for repair between 10 and 18 September, with Perth to Sydney traffic on land routes meanwhile. Bevan Slattery, founder of the cable company SUBCO, reported the two August faults on the INDIGO systems to the Australian Federal Police, saying it "could be a coincidence or an external aggression event". The AFP said on 11 August it had received a report of crime and was assessing it. Nothing on the record connects that to Friday's break, and Vocus has made no attribution of any kind.
What is known is that Australia's west coast has two direct cables to Asia and neither is working. What is not known is how long that lasts. Repair ships are few, Indonesian permits take time, and Vocus has committed only to another update on Friday.
