Tajikistan opens a fibre route to China over the Kulma pass with up to 1 Tbps at the start

Dushanbe to Beijing, through Khorog and the Kulma pass: 1,010 km of new fibre on the Tajik side, opened on 17 October with an initial capacity of up to 1 Tbps. State-owned Tajiktelecom and China Mobile International signed the documents and started the line at a ceremony at the Communications Service under the Government of Tajikistan, Avesta reported, citing the Tajik operator.

The route runs Dushanbe, Khorog, Kulma, Karasu and Beijing. Of the 1,010 km in Tajikistan, 435 km cross the high mountains of the Gorno-Badakhshan Autonomous Region, and the Tajik network meets China's at the Kulma pass, at 4,363 m. The Chinese segment from Beijing to the border is about 6,100 km, the report says. Corridor Signal has not seen a route map from either operator.

Initial capacity, and what is only planned

The first stage uses a 16-fibre cable with DWDM equipment, which gives the initial capacity of up to 1 Tbps. Capacity is to rise to 10 Tbps as more multiplexing equipment is installed, Avesta reports, and the infrastructure's technical potential runs to several hundred Tbps in the longer term. Both are plans, not built capacity, according to Avesta and Fergana, which attributes the launch announcement to the Communications Service. The line also connects Tajiktelecom directly to the Hong Kong Internet eXchange, HKIX, and is the country's fifth international connection point, both reports say.

Tajikistan's stated goal is 2 Tbps of total international capacity by 2030, according to Avesta. The new route on its own, at full initial load, would supply half of that. In July the head of the Communications Service, Isfandiyor Sadullo, put international bandwidth at 500 Gbps, double the level of a year earlier, The Times of Central Asia reported. The two figures measure different things: 500 Gbps is the country's international bandwidth across all its routes, while 1 Tbps is the initial ceiling of one route, so they cannot be added together.

From 2 Gbps to a terabit

The scale of the change shows in an older baseline. A 2014 study for the UN Economic and Social Commission for Asia and the Pacific estimated Tajikistan's international bandwidth at 2 to 3 Gbps at the end of 2012, recorded fibre links to Afghanistan, Kyrgyzstan and Uzbekistan, and said a link to China was reportedly under way but could not be confirmed as active, according to the ESCAP study. It also found that none of the neighbouring markets offered affordable IP transit.

The line was later than officials had said. In August the Communications Service said the trunk line and its new international connection point would be fully operational by the end of September 2026, the agency Prime reported, citing the state news agency Khovar. The launch came on 17 October.

What is not published

None of the reports gives the project's cost or how it was financed, the price of transit on the route, how much of the 1 Tbps is already sold, or whether other Tajik operators can buy capacity on it. The fibre's link to the domestic network matters for that last question: the European Bank for Reconstruction and Development is considering a sovereign loan of up to EUR 48.4 million for Tajikistan's fibre backbone and open-access rural broadband, Corridor Signal reported, with an approval date of 16 December.

The route also bears on how traffic is exchanged at home. Tajikistan had the highest share of networks connected to a local exchange point among the corridor's countries in the Internet Society data Corridor Signal compared, and the HKIX link adds a direct path to an exchange in Hong Kong. The Corridor Capacity Tracker covers subsea routes and does not yet track terrestrial lines such as this one.