The SEA-ME-WE 4 consortium began building a new submarine fiber route linking Southeast Asia, the Middle East, and Western Europe. Fujitsu and Alcatel Submarine Networks (now part of ASN) were contracted to construct the system, setting the project’s technical plan and build schedule.
After the December 2004 earthquake and tsunami near Sumatra, parts of the planned route required rechecking. The builders resurveyed the seabed and confirmed the route remained usable, reducing the risk of laying cable on unstable terrain.
A major segment of cable-laying between Jeddah, Fujairah, Karachi, and Mumbai was reported completed during construction. Finishing this long block helped de-risk the overall project by proving that key ships, permits, and procedures were working.
The consortium’s roughly 20,000 km system was announced as completed, and an inauguration ceremony in Dubai marked the start of telecommunications services. At launch, the design capacity was stated as 1.28 Tb/s, reflecting the system’s original wavelength (channel) plan.
Damage to SEA-ME-WE 4 and another major cable in the Mediterranean caused widespread slowdowns and outages across parts of the Middle East and South Asia. The event highlighted how a small number of cable routes—especially those crossing chokepoints—can become single points of failure.
France Télécom reported that several major submarine cables, including SEA-ME-WE 4, were cut in the Mediterranean within minutes of each other. Operators rerouted traffic, but capacity was reduced and performance degraded for many users and businesses.
After a repair was completed, SEA-ME-WE 4 broke again at a different location and much greater depth off Egypt. The extra break delayed full restoration and showed that large outages can involve multiple faults, not just a single cut.
The co-owners selected Alcatel-Lucent and Ciena for a major expansion using higher-speed optical technology. The plan included 40G transmission on submarine segments and a 100G upgrade to the terrestrial link across Egypt, a critical land bridge between the Red Sea and Mediterranean segments.
The SEA-ME-WE 4 Network Administration System was described as a software platform used by the community of bandwidth users for tasks like requests and reporting. This reflects how mature cable systems rely on operational tooling—not just wet-plant cable—to manage capacity and service delivery.
SEA-ME-WE 4 announced completion of a major upgrade using Ciena’s GeoMesh Extreme submarine solution. The stated capacity increase (from 65 Tb/s to 122 Tb/s) shows how modern coherent optics can dramatically expand throughput without laying a new transcontinental cable.
Pakistan’s National Assembly was told that an offshore erosion event near Karachi caused a large loss of capacity on SEA-ME-WE 4 and ongoing disruptions. The report underscores that seabed movement and coastal conditions can be as damaging as ship anchors.
By the mid-2020s, SEA-ME-WE 4 continued operating as an active Asia–Europe route while newer systems (such as SEA-ME-WE 6) were being built to add more capacity and resilience. The outcome is a layered network: older cables like SEA-ME-WE 4 stay valuable through upgrades, while new cables reduce congestion and provide alternate paths during faults.
SEA-ME-WE 4 (2005–present) — deployment and upgrades