Bawean, Indonesia: no other cable lands within 50 km.
On an island this means losing the submarine link; on the mainland traffic can still go over land.
No alerts from our monitoring on this cable in the last 180 days. Events feed →
Counted: other international cables landing in the same country (domestic cables between points of one country are not a way out), other cables at landing points within 50 km, and whether the country has land links. Not counted: cable capacity, operator contracts and satellite. Use as a first look at dependence, not as a statement of what would happen.
Live Performance
390
measurements
8
probes
96
days monitored
286.1
ms avg RTT
0
anomalies
Monitored from 2026-07-14 through 2026-10-18 - live ICMP round-trip time measurements via our monitoring probes. All values below are recomputed daily from raw probe data. ✓ No anomalies detected in the monitored period.
Measurement sources
Probe
Location
Samples
Avg
Min-Max
Last seen
#6427 own probe
Sydney AU
129
266.2 ms
114.6-490.4
2026-10-18
#6410 own probe
Sao Paulo BR
127
395.6 ms
356.4-794.3
2026-10-18
own probe
Almaty KZ
80
276.3 ms
254.9-393.2
2026-10-05
#6568 own probe
Singapore SG
20
25.2 ms
23.9-33.0
2026-10-18
#6487
control probe
18
23.3 ms
22.4-24.8
2026-08-25
own probe
Jerusalem IL
11
229.2 ms
218.7-267.1
2026-09-07
own probe
Tbilisi GE
3
327.3 ms
321.3-331.9
2026-09-05
own probe
Minsk BY
2
239.2 ms
238.5-239.9
2026-07-14
About the SJJK Cable System
SJJK: A Domestic Submarine Cable Connecting Indonesian Islands
The SJJK submarine cable is a domestic telecommunications system connecting multiple locations in Indonesia. Owned by XLSmart, it spans 543 km and is listed as in service. Its landing points include Anyer, Bawean, Kalianda, Takesung, and Ujung Pankah, all located within Indonesia. While the cable's design capacity, fiber pair count, supplier, and technology are not publicly disclosed, it serves as an important regional infrastructure linking these islands.
What makes SJJK particularly interesting is the absence of detailed technical specifications in public records, which is unusual for submarine cables. Additionally, its ready-for-service (RFS) year is recorded in the GeoCables database as 2008, but there may be conflicting information in industry sources. Public latency measurements from remote probes highlight the cable's role within a broader network, but they do not isolate the cable's performance itself.
The SJJK cable connects five landing points within Indonesia: Anyer, Bawean, Kalianda, Takesung, and Ujung Pankah. These locations span several islands, forming a domestic corridor that facilitates communication between Java, Sumatra, and other parts of the archipelago. Anyer and Kalianda are located on the island of Java, Bawean lies to the north in the Java Sea, and Takesung and Ujung Pankah are also situated within the region. The cable's route is entirely within Indonesian waters, making it a domestic infrastructure project.
Why it was built and what it carries
The SJJK cable was likely constructed to enhance domestic connectivity between Indonesian islands, supporting the country's growing demand for broadband and telecommunications services. Indonesia's geographical layout, with thousands of islands, necessitates submarine cables for reliable inter-island communication. While the exact data it carries is not disclosed, such cables typically support internet traffic, voice communications, and enterprise data services.
History: what can be established
The GeoCables database records the SJJK cable's ready-for-service year as 2008. If industry sources suggest a different year, the discrepancy could arise from delays in documentation, phased activation of segments, or differing definitions of "ready-for-service." As of now, no alternative RFS year has been surfaced in public sources. XLSmart is listed as the owner, but further details about the company's role in the cable's development or operation are not readily available.
Capacity and technology
Publicly available data does not disclose the SJJK cable's design capacity, fiber pair count, supplier, or specific technology. Without operator documentation, attributing these parameters would be speculative. Submarine cables of this type often use dense wavelength division multiplexing (DWDM) technology to maximize capacity, but this cannot be confirmed for SJJK.
Latency: the physics
Theoretical latency for light propagation over the SJJK cable's 543 km wet segment is approximately 2.7 ms one-way and 5.3 ms round-trip (RTT), assuming optimal fiber speeds of 200,000 to 204,000 km/s. Real-world latency is higher due to land tails, terminal equipment, and routing. Live measurements from remote probes show significantly higher RTTs, such as 24.3 ms between Singapore and Ujung Pankah. These values reflect the full internet path, including terrestrial and other submarine segments, rather than the SJJK cable alone.
Redundancy: what happens if it breaks
In the event of a failure, redundancy within the corridor is provided by other cables landing at overlapping points. For example, Anyer hosts the Australia-Singapore Cable (ASC) and Biznet Nusantara Cable System-1 (BNCS-1), while Kalianda is also served by BNCS-1. Takesung connects to the Java-Kalimantan-Sulawesi (JAKASUSI) cable. Repairs to submarine cables typically involve specialized ships equipped with remotely operated vehicles (ROVs) for locating and fixing faults. However, repair logistics for SJJK specifically are not documented.
Bottom line
SJJK is a domestic submarine cable connecting five Indonesian landing points: Anyer, Bawean, Kalianda, Takesung, and Ujung Pankah.
Its length is 543 km, and it is listed as in service with an RFS year of 2008 (GeoCables database).
Design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
Theoretical latency is 2.7 ms one-way and 5.3 ms RTT over the wet segment, but real-world RTTs are higher due to additional network factors.
Redundancy is provided by overlapping cables at certain landing points, such as ASC, BNCS-1, and JAKASUSI.