S-U-B Cable System: connecting key Indonesian cities
The S-U-B Cable System is a submarine telecommunications cable linking three major cities in Indonesia:
Banjarmasin,
Makassar, and
Surabaya. Spanning approximately 2009 kilometers, it is owned by Telkom Indonesia and has been recorded as operational since 2008 according to GeoCables data. This cable plays a role in the country's domestic connectivity, facilitating communication and data exchange across the archipelago.
What stands out about the S-U-B Cable System is the limited publicly available information regarding its technical specifications, such as design capacity, fiber pairs, and supplier. This lack of transparency is not uncommon for domestic cables, which often receive less international scrutiny compared to transoceanic systems. Additionally, while GeoCables lists its ready-for-service year as 2008, conflicting dates from other industry sources are possible, and these would require further investigation to resolve.
Quick facts
| Name | S-U-B Cable System |
| Length | 2009 km |
| Ready-for-service year | 2008 (GeoCables database; potential conflicts not surfaced) |
| Owner | Telkom Indonesia |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Landing points | Banjarmasin, Makassar, Surabaya (all in Indonesia) |
Route
The S-U-B Cable System connects three Indonesian cities:
- **Banjarmasin**, located on the island of Borneo, a critical hub for the region's economy and communications.
- **Makassar**, situated on Sulawesi, serving as a major gateway for eastern Indonesia.
- **Surabaya**, on the island of Java, one of Indonesia's largest cities and a key economic center.
This route spans diverse geographic and marine environments, reflecting Indonesia's status as an archipelagic nation. The cable's path likely traverses shallow waters near the coasts, with deeper sections in the Makassar Strait.
Why it was built and what it carries
The S-U-B Cable System was built to enhance domestic connectivity between key urban centers in Indonesia. As Indonesia consists of over 17,000 islands, submarine cables are essential for linking regions separated by vast stretches of ocean. This cable supports the increasing demand for broadband internet, mobile data, and other telecommunications services in a growing economy.
While specific details about its traffic composition are not disclosed, it is reasonable to infer that the S-U-B Cable System carries a mix of consumer internet traffic, corporate data, and government communications. Its role complements other domestic and international cables landing in the same cities, such as the
Indonesia Global Gateway (IGG) System and
Trans Global Cable System (TGCS).
History: what can be established
GeoCables data records the S-U-B Cable System as ready for service in 2008, but potential discrepancies with industry sources are worth noting. If alternative dates exist, they might arise from differences in definitions of "ready-for-service" (e.g., technical completion versus commercial launch) or delays in documentation. Telkom Indonesia's ownership of the cable aligns with its position as a major telecommunications provider in the country.
Capacity and technology
Publicly available information does not disclose the cable's design capacity, number of fiber pairs, or supplier. Without operator documentation, attributing specific technological details would be speculative. Given its domestic scope, the cable likely employs standard optical fiber technology, but whether it includes advanced features such as wavelength division multiplexing (WDM) is unknown.
Latency: the physics
The theoretical one-way light propagation time over the cable's 2009 km length is approximately 9.8 milliseconds, with a round-trip time (RTT) floor of 19.7 milliseconds. However, real-world latency is higher due to factors such as land-based network tails, terminal equipment delays, and routing inefficiencies.
Live measurements from remote probes provide insight into end-to-end latency for internet traffic involving Surabaya:
- Singapore to Surabaya: 24.4 ms (minimum and average).
- Sydney to Surabaya: 116.7 ms (minimum and average).
- Almaty to Surabaya: 274.4 ms (minimum and average).
- Tbilisi to Surabaya: 316.2 ms (minimum and average).
- Minsk to Surabaya: 239.7 ms (minimum and average).
- Sao Paulo to Surabaya: 384.1 ms (minimum and average).
These figures reflect the full internet path, not just the submarine cable segment.
Redundancy: what happens if it breaks
If the S-U-B Cable System experiences a fault, redundancy is available through other cables landing at its endpoints:
- **Banjarmasin**:
Barat Timur Indonesia-2 (BTI-2),
JaKa2LaDeMa.
- **Makassar**:
Asia Connect Cable-1 (ACC-1),
Barat Timur Indonesia-1 (BTI-1), Indonesia Global Gateway (IGG) System,
Indonesia Tengah Cable Systems, Trans Global Cable System (TGCS).
- **Surabaya**: Trans Global Cable System (TGCS).
Repairing submarine cables typically involves deploying specialized cable ships to locate, retrieve, and fix the damaged segment. This process can take weeks, depending on the fault's location and severity.
Bottom line
- The S-U-B Cable System spans 2009 km, connecting Banjarmasin, Makassar, and Surabaya in Indonesia.
- Owned by Telkom Indonesia, it has been recorded as operational since 2008, though date conflicts are possible.
- Technical specifications such as design capacity, fiber pairs, and supplier are not publicly disclosed.
- Its theoretical RTT floor is approximately 19.7 ms, but real-world latency is higher due to additional network factors.
- Redundancy is available through other cables landing at its endpoints.