Darwin-Jakarta-Singapore Cable (DJSC): A regional link connecting Australia and Southeast Asia
The Darwin-Jakarta-Singapore Cable (DJSC) is a submarine telecommunications cable that connects
Darwin and
Port Hedland in Australia to
Jakarta in Indonesia and
Singapore. Owned by Vocus Communications, it spans approximately 1,000 kilometers and is listed as in service as of 2023. This cable enhances connectivity between Australia and Southeast Asia, serving as an important regional link.
What stands out about DJSC is the limited publicly disclosed technical information. Key details such as its design capacity, fiber pair count, supplier, and technology remain unknown, leaving room for speculation and highlighting the challenges of analyzing submarine cable systems without operator-provided documentation. Additionally, the cable's latency performance and redundancy options are of interest, particularly given the crowded nature of the landing points it shares with other cables.
Quick facts
| Length | 1,000 km |
| Ready for Service (RFS) | 2023 (GeoCables database) |
| Owner | Vocus Communications |
| Status | In service |
| Design Capacity | Not disclosed |
| Fiber Pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing Points | Darwin (Australia), Jakarta (Indonesia), Port Hedland (Australia), Singapore (Singapore) |
Route
The DJSC connects four landing points: Darwin and Port Hedland in Australia, Jakarta in Indonesia, and Singapore. Darwin and Port Hedland are key locations in northern and western Australia, respectively, while Jakarta and Singapore are major hubs for telecommunications in Southeast Asia. The cable's route provides a direct connection between these regions, facilitating data exchange and enhancing international connectivity.
Why it was built and what it carries
The DJSC was built to improve telecommunications infrastructure between Australia and Southeast Asia. By linking Darwin and Port Hedland to Jakarta and Singapore, the cable supports international data traffic, including internet, voice, and enterprise services. This corridor is strategically significant for both regional connectivity and global data exchange, given the growing demand for bandwidth between these regions.
History: what can be established
The GeoCables database lists the DJSC as ready for service in 2023. However, submarine cable projects often face delays due to factors such as permitting, marine surveys, or installation challenges. If industry sources suggest a different RFS year, it would be important to explore potential causes for the discrepancy, such as phased commissioning or revisions to project timelines. At present, no conflicting information about the RFS date has been identified.
Capacity and technology
Publicly available data does not disclose the design capacity, fiber pair count, supplier, or specific technology of the DJSC. Without operator documentation, it is impossible to confirm these details. Submarine cables typically use dense wavelength division multiplexing (DWDM) technology to maximize capacity, but attributing this to the DJSC without evidence would be speculative.
Latency: the physics
The theoretical one-way light propagation latency over the DJSC's 1,000 km wet segment is approximately 4.9 milliseconds, with a round-trip time (RTT) floor of 9.8 milliseconds. Real-world latency is higher due to additional factors such as land tails, terminal equipment, and routing.
Live measurements from remote probes, which capture the full internet path rather than the cable itself, indicate significantly higher RTTs. For example:
- Singapore to Darwin: Minimum 92.6 ms, average 132.2 ms over 59 checks.
- Sydney to Darwin: Minimum 0.2 ms, average 0.2 ms over 10 checks (WARNING: the minimum is below the physical floor of 9.8 ms and is a measurement artifact caused by rate-limited ICMP replies).
- Sao Paulo to Darwin: Minimum 307.3 ms, average 307.5 ms over 10 checks.
These values reflect the broader internet path and should not be interpreted as the cable's performance. The artifact in the Sydney-Darwin measurement highlights the importance of careful analysis when interpreting latency data.
Redundancy: what happens if it breaks
The DJSC's landing points are shared with several other submarine cables, offering redundancy in case of outages or maintenance. For example:
- Darwin: Asia Connect Cable-1 (ACC-1), Bosun, Hawaiki Nui 1, North-West Cable System, Project Waterworth.
- Jakarta: Asia Connect Cable-1 (ACC-1), Bifrost, Hawaiki Nui 1, INDIGO-West, Indonesia Global Gateway (IGG) System, Jakarta-Bangka-Batam-Singapore (B2JS), Jakarta-Bangka-Bintan-Batam-Singapore (B3JS), JaSuKa, Matrix Cable System.
- Port Hedland: North-West Cable System.
- Singapore: Asia Connect Cable-1 (ACC-1).
Redundancy is critical for maintaining service continuity, as cable breaks can occur due to natural events, such as earthquakes or fishing activities, or human activities like anchoring. Repairs typically involve deploying specialized cable ships to locate, retrieve, and repair damaged sections.
Bottom line
- The Darwin-Jakarta-Singapore Cable (DJSC) spans 1,000 km and connects Australia to Southeast Asia.
- Owned by Vocus Communications, it is listed as in service as of 2023.
- Technical details such as design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
- Theoretical latency over the wet segment is approximately 4.9 ms one-way, but real-world RTT is higher due to additional factors.
- Redundancy is provided by several other cables at the landing points.