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World’s Critical Infrastructure

After all the unexplainable outages that undersea cables have severed, I thought it would be essential to highlight a brief history about who owns the oceans including some pointers about global undersea communication cables aka world’s critical infrastructure.

Who owns the oceans? It is codified as “the common heritage of all mankind” [Source: UN].

International law

Undersea cables are protected by international treaties: the International Convention for Protection of Submarine Cables of 1884, the Geneva Conventions of the Continental Shelf and High Seas of 1958 and the U.N. Convention on the Law of the Sea [UNCLOS] of 1982.

The treaties provide freedom to lay, maintain, and repair cables outside of a nation’s 12 nautical mile (13.8 miles and 22.2 km) territorial sea and obliges nations to impose criminal and civil penalties for intentional or negligent injury to cables. In order to reduce risk, cables are identified on nautical charts and may be placed within a “protection zone” where activities harmful to cables are banned.

These legal boundaries of the oceans can be summarized as follows:

Territorial sea: Boundary along a nation’s coast that extends its terrestrial boundaries, was set at 12 nautical miles (13.8 miles and 22.2 km). This is the shallow area of continental shelf (about 200m or 650 feet) compared to the continental slope that could go several thousand feet deep. UNCLOS (3).

Exclusive economic zone (EEZ): Territorial waters are extensions of a state’s laws and right of defense; EEZs are extensions of a state’s rights to resources offshore. The boundaries of an EEZ go well beyond territorial waters, extending 200 miles (322 km) from shore. U.N. have widen this by allowing nations with wide continental shelves to extend
their EEZ up to 350 miles (563 km) from shore. UNCLOS (58, 113-115).

A brief history of undersea cables:

1850: First international telegraph link, England-France, later cables joined other European countries & USA with Canada.

1858: First trans-Atlantic cable laid between Ireland & Newfoundland; failed after 26 days & new cable was laid in 1866.

1866: First trans-Atlantic (copper) cable carried telegraph messages at 12 words a minute. These cables were promoted as the eighth wonder of the world emphasizing cooperation between UK and the United States.

1884: First underwater telephone cable service from San Francisco to Oakland.

1920: Short-wave radio superseded cables for voice, picture & telex traffic.

1956: First trans-Atlantic (TAT-1) telephone cable initially had a capacity of 36 telephone calls at a time; calls cost $12 for the first 3 minutes. Invention of repeaters (1940s) & their use in TAT-1.

1961: Beginning of high quality, global network.

1986: First international fiber-optic cable joins Belgium & UK.

1988: First Atlantic fiber-optic cable, TAT-8, had a capacity for 40,000 simultaneous phone calls, 10 times that of the last copper cable. This is when submarine cables started to outperform satellites in terms of the volume.

Today: Each fiber pair within a cable has the capacity to carry information including video that is equivalent to 150,000,000 simultaneous phone calls. Almost all transoceanic telecommunications are now routed via the submarine cable network instead of satellite.

SEA-ME-WE = South-East Asia - Middle-East - Western Europe Submarine Cable System. The Submarine Cable System has eight segments and it is one of the longest submarine cables in the world. The following three cables—SeaMeWe-3, SeaMeWe-4, and FLAG Europe-Asia—link the Middle East to Europe. Since these three cables follow similar paths through the Mediterranean, they are vulnerable to some of the same physical threats but traffic is rarely 100% affected. There are two different routes—Mediterranean and Pacific but unfortunately Trans-Pacific is not balanced in terms of bandwidth and fiber capacity. There are other private systems that are well architected and balanced in terms of bandwidth and failover but club cables like SeaMeWe and FLAG are the product of incumbent telcos. SeaMeWe-4, accounts for almost 90% of currently lit capacity.

The concept of Sonet/SDH protective rings has been around for over 15 years, yet most subsea cable systems built over the last decade are not built on redundant topologies and this comes down to cost. This is starting to change, five new cables are scheduled to enter service between Europe and Egypt in 2010. The first two, Telecom Egypt’s TE North cable and the IMEWE consortium cable, will enter service mid-2010 between Mediterranean and Red Sea. Europe India Gateway consortium cable likely to enter service before mid 2010 and the google backed Unity cable across the Pacific which is planned for launch by 2010. By year-end 2010 SeaMeWe-4 will account for only about 40% of lit capacity between Europe and the Middle East.

Cable faults

Unfortunately there is no global database that undersea cable faults are tracked. There’s ICPC and other organizations that track such outages or faults but nothing central that one could lookup. It appears that most faults occur on the continental shelf in depths of less than 200 meters.

I guess one could expect this due to vast majority of human activities that involve seabed contact that takes place in relatively shallow waters. The remaining faults occur across a wide range of depths, including oceanic areas more than 4,000m deep off continental slope.

According to the Submarine Cable Improvement Group, about 70% of all cable faults are from fishing and anchoring while natural hazards such as chafing and earthquakes account for 12% of faults.


Given the world’s cross-border internet and telephone traffic that submarine cable systems provide it is important to recognize the importance of undersea cables to the world’s infrastructure. As the global economy (Communications, Education, Business, Entertainment, Banking & Commerce) continues to be dependent on undersea cables, it should be regarded as the world’s critical infrastructure and held to the same standard as land-based counterparts of the Internet. Countries rely on undersea cables for over 95 percent of its international voice and data traffic while only 7 percent of which could be carried via satellite in the event of cable disruption which is insufficient to handle the traffic volume.

There should be a collective interest among operators (cooperation between all stakeholders) in continuing to make sure all paths are well balanced along different routes to provide diversity in case of localized damages and until new routes are opened up, these types of outages will continue to cause di$ruption.

By Virendra Rode, Network Consultant

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