Malbec

Malbec is a 2,880 km submarine cable connecting Argentina and Brazil, with one landing in Argentina (Las Toninas) and three in Brazil (Porto Alegre, Praia Grande, Rio de Janeiro). Ready for service in 2021, Malbec is jointly owned by Meta (the Facebook parent) and V.tal, Brazil's neutral wholesale fibre operator. It is a short, young, private cable — built to directly serve a single commercially valuable corridor rather than to form part of a regional backbone.

The ownership split tells you most of the economic story. Meta is one of the largest hyperscalers operating its own subsea infrastructure; V.tal is what used to be the passive fibre network of the Brazilian incumbent Oi, carved out in 2022 into a neutral wholesale carrier that sells capacity to any paying customer without running competing retail services. Together they built a cable that Meta needed for its own South American traffic and that V.tal could monetise by selling the surplus capacity to other carriers serving the Argentina–Brazil corridor.

25 ms on a 2,880 km path — near the physics floor

Our monitor samples Malbec between Las Toninas (Argentina) and Rio de Janeiro (Brazil) — the two endpoints of the cable system. Twenty-seven samples over thirty days produced a split picture:

The theoretical physics floor for a 2,880 km fibre path is 28.19 ms round-trip. Our once-observed minimum of 25.36 ms sits below that floor — a signal that the path taken during that measurement used only a sub-segment of the full cable body, not the full 2,880 km. Malbec has four landings and a trunk-and-branch topology: the direct Argentina-to-Rio segment is shorter than the full cable length, because some of the 2,880 km is accounted for by the branches to Porto Alegre and Praia Grande.

After March 28, the forward direction settled onto a longer path — the 36.34 ms at 13 hops that we have observed consistently since April 11. That is 1.29× the physics floor on the full cable length, or roughly a 43% increase over the brief March path. The most likely explanation is a route change at one of the Argentine upstream carriers, adding three hops and about 11 ms of extra fibre to the forward direction. The reverse direction (Rio → Las Toninas) has been consistently around 49 ms with 17 hops throughout, independent of the forward-direction change.

The 13 ms asymmetry and why return paths in Latin America are often longer

Forward 36 ms vs reverse 49 ms gives a 13 ms asymmetry gap with the current routing. This is a small-to-moderate asymmetry — consistent with what we see on other point-to-point Latin American cables — and reflects the reality that southbound and northbound traffic on the Argentina–Brazil corridor do not always take the same physical path.

Historically, Latin American internet traffic has shown significant asymmetry for one structural reason: for many years, the cheapest peering and transit options for South American ISPs were at exchange points in the United States, not within South America itself. Traffic leaving Argentina often hairpinned through Miami even to reach a destination one country away; the return path would take a more direct route because the destination network had local Brazilian upstream. The pattern has been shrinking as regional IXPs at São Paulo and Buenos Aires have grown, but it persists for smaller carriers and older routing contracts. The 13 ms gap on Malbec is probably an asymmetry of routing policy, not fibre — both directions do use Malbec itself at the submarine layer, but different IP-layer paths on land add different amounts of fibre before and after.

Four landings, two countries

Three Brazilian landings on a 2,880 km cable is unusually dense. The cable is essentially a trunk from Las Toninas up the Brazilian coast, with branches or direct landings at each of the three major Brazilian data-centre markets. That reflects the structure of Brazilian demand: three primary metropolitan regions (São Paulo, Rio, and Porto Alegre) each with their own concentration of data centres and peering infrastructure. Rather than landing at a single Brazilian site and backhauling, Malbec lands at each market directly — reducing the terrestrial fibre kilometres that traffic needs to traverse to reach its destination.

The Meta + V.tal model

Malbec is one of a family of cables that Meta has directly funded or co-funded, alongside Marea (Atlantic, with Microsoft and Telxius), Apricot (intra-Asia), Bifrost (trans-Pacific), and 2Africa (around Africa). The model is consistent across these: Meta provides the anchor capacity commitment that makes the project financeable; the cable is built to carrier-grade standards; Meta gets private fibre pairs for its own use; remaining capacity is sold wholesale.

V.tal's involvement is the more novel part. Neutral wholesale fibre operators — carriers that own and lease infrastructure but do not sell retail services in competition with their customers — are a relatively new business model in Latin America. V.tal was carved out of Oi's fibre assets as part of Oi's 2022 restructuring, and has since attracted investment from BTG Pactual and Globenet. For Meta, partnering with V.tal means no competition with the operating partner for domestic Brazilian customers; for V.tal, anchoring its capacity with a Meta commitment de-risks the economic case.

Malbec in the Latin American cable landscape

Compared with older Latin American cables, Malbec is a narrow, purpose-built specialist. South American Crossing (2000) is a 22,000 km loop around the entire continent with twelve landings. AMX-1 (2014) is a 17,800 km coastal cable covering the Atlantic and Caribbean. SPCS/Mistral (2021) serves the Pacific coast. Malbec is 2,880 km serving one corridor — Argentina to Brazil — at the physics floor.

That narrowness is the point. The hyperscaler cable-building playbook that Meta uses here is the opposite of the 2000s consortium model: instead of one long cable serving many markets at medium capacity per pair, build a short cable serving one market at high capacity per pair, dedicated primarily to the anchor customer's traffic. The two models coexist, but Malbec's generation — short, private, high-capacity — is what new capital is flowing into.

What our data proves

• Argentina → Brazil at 36 ms minimum, 13 hops, currently running at 1.29× physics floor. A shorter 25 ms path was briefly observed in late March before an upstream reroute.
• 13 ms reverse asymmetry. Rio → Las Toninas consistently ~49 ms while Las Toninas → Rio is ~36 ms. IP-layer asymmetry, not fibre-layer.
• Meta + V.tal ownership. Hyperscaler anchor plus neutral-wholesale-fibre partner — a model that is reshaping Latin American submarine infrastructure economics.

Try it yourself

Live measurements on the Malbec cable page. Compare with the long coastal predecessors — SAC's continental loop and AMX-1's eight-country coastal ride — and with the other Meta-funded cable in our catalogue, Marea. Malbec's narrow specialisation is visible next to the older generation's broad coverage; the two approaches are answers to different commercial questions.