Subsea Cables & Internet Infrastructure

 At the 2026 Submarine Networks World in Singapore Ciena pitched the MOFN business model, the managed optical fiber network. This is a network dedicated to a single customer like a hyperscaler, large enterprise, government, and the like. It involves dedicated fibre pairs and equipment. Very often the customer buys the equipment and ships it to the network operator. It is quite common in Africa where network operators provide such services to the American Tech Giants. But carriers have often found that hyperscaler forecasts of capacity needs are often wildly off. The result is poor MOFN economics and low rates of return.

Ciena seems correct when it asserts massive growth from here to 2035. Heck, that is a 35 year Internet trend. But claiming that traffic will be 85% AI sounds like a very bad forecast. Right now the world is spending $2 trillion each year on AI infrastructure versus $100 billion in AI service revenues. A pretty big gap. We have experienced cycles of excess technology enthusiasm over the last 150 years and bullish forecasts have almost always proved wrong. 

Southern Cross subsea cable system is implementing ODUflex, which is a relatively new ITU standard that allows granular Layer 1 bandwidth. No longer are we limited to 100G, 400G, and 800G for either subsea or terrestrial networks. Interestingly enough, Hauwei proposed the new standard and was its primary champion. All wavelengths consist of optical containers and ODUflex allows optical containers to be stacked at 1.25 Gps intervals. So you can lease 1.25 Gbps wavelength up to 400G in 1.25 Gbps increments. Note that port sizes are still 10G, 100G, 400G or 800G. So to access a 150G transmission rate the customer needs 400G intefaces. Ciena is one of the the vendors to implement ODUflex along with Hauwei. More details here: https://lnkd.in/dZvNbubc. It is worth noting that granular bandwidth is being implemented on the newer cables which Southern Cross owns like Next.  The commercial motivation is poor take up of 400G wavelengths. The only real customers for 400Gs are very big bandwi...