Why Physical Proximity Fails to Guarantee Local Traffic in African Cloud Markets

Across African tech hubs, the expansion of data centres and cloud regions rests on a straightforward commercial premise: placing servers closer to users delivers faster connections and lower costs. Physical proximity on a map, however, does not dictate how data travels across the internet. Network measurements presented using the TANGLED anycast testbed  show that even when a server node is located in Lagos or Johannesburg, traffic from neighbouring countries can still be routed through European transit infrastructure before returning to the continent.

For cloud investors, internet service providers, and telecommunications regulators, this routing behaviour reveals a structural limit: building local data centres is necessary, but it does not guarantee that regional traffic will reach them.

The Disconnect Between Compute Location and BGP Routing

The deployment of local cloud points of presence assumes that physical distance determines network performance. Testing conducted on the TANGLED anycast network, which uses identical IP addresses across multiple global server nodes, challenges that assumption.

In an anycast design, incoming traffic relies on the Border Gateway Protocol to select a path to a server. Measurements using the TANGLED testbed  (with nodes in Lagos and Johannesburg) recorded a median round-trip latency of 46 milliseconds for African networks, compared with a global median of 25 milliseconds. In the tests, networks in adjacent West African countries routed requests to a node in Paris rather than handing traffic directly to the active server node in Lagos.

The measurements indicate that installing server hardware inside a market does not automatically override the path selections made by surrounding network providers.

Historical Cable Paths and Commercial Contracts

The routing patterns observed are driven by historical subsea cable paths and existing commercial agreements. Early subsea fibre systems were built primarily to connect African markets to European hubs—London for many Anglophone routes and Paris for many Francophone routes—rather than to establish dense direct links between neighbouring African countries. Border Gateway Protocol routes follow commercial peering and transit contracts more than pure geographic distance.

Internet service providers in neighbouring markets frequently maintain long-term international transit contracts with global tier-1 carriers. Because cross-border traffic exchange between adjacent African nations remains limited, local providers continue to route data through established European transit paths even when a physical server operates in a nearby country.

Commercial Risks Facing Regional Cloud Regions

When traffic destined for a local data centre still leaves the continent, the performance and cost benefits expected from regional cloud investments are reduced. Latency increases, international capacity is consumed, and revenue that could support local interconnection flows to overseas transit providers. The TANGLED measurements illustrate that a server presence in Lagos or Johannesburg does not, by itself, ensure that traffic from neighbouring markets stays local.

Institutional Outlook for Traffic Localisation

Addressing the routing patterns requires changes in the commercial incentives that govern traffic exchange, not only additional server capacity. Regional initiatives show that traffic can remain local when interconnection structures support it. Facilities such as NAPAfrica  in South Africa and the Internet Exchange Point of Nigeria  have demonstrated that expanded local peering lowers transit costs and reduces connection delays. International exchange operators that offer free or low-cost local access in markets such as Accra are also working to encourage carriers to exchange traffic within the region rather than exporting it.

For regulators and infrastructure investors, performance metrics need to include actual localised traffic exchange in addition to data-centre floor space. Until cross-border peering agreements expand and replace reliance on legacy European transit paths, geographic proximity and network performance will remain distinct.