Network Infrastructure


Two decades of experience and expertise

As part of its network offerings, TENET operates the South African National Research Network (SANReN) that has been deployed over the past ten years by the SANReN Competency Area (SCA) under contract to the Department of Science and Technology (DST). SANReN comprises a national backbone, multiple metropolitan rings, and extensive long-haul circuits to reach important research installations. These components are described briefly below. More information is available on the SCA website.

The original SANReN national backbone was commissioned in December 2009 and comprised a 10 Gbps ring interconnecting Pretoria, Johannesburg, Bloemfontein, Cape Town, Port Elizabeth, East London and Durban. The network has since been significantly extended through a combination of DST, DHET, TENET and institutionally funded circuits to both increase aggregate network capacity to well over 1Tbps and to reach university campuses in smaller towns in all nine provinces.

SANReN’s metro fibre optic ring networks in Johannesburg, Pretoria, Cape Town and Durban were fully commissioned by 2010. In aggregate they connect some 90 urban campuses to the backbone. Dedicated access circuits include high capacity long-haul circuits to the Hartebeesthoek Radio Astronomy Observatory (HartRAO), the South African Astronomical Observatory (SAAO) in Sutherland, the South African National Space Agency (SANSA)'s magnetic observatory in Hermanus, and the developing Square Kilometre Array (SKA) site in Carnarvon.

Between 2010 and 2019, the Rural Campuses Connection Project (RCCP) was undertaken to provide high-bandwidth connections for rural university campuses to SANReN. TENET acted as implementation agent for the then Higher Education South Africa (HESA), now Universities South Africa (USAf), in both RCCP I and II.

The South African NREN network also includes access circuits that TENET itself provides for many campuses. These include optical fibre access circuits that connect campuses which were not beneficiaries of any other connectivity initiative, to the nearest SANReN node.

We use multiple submarine circuits to provide intercontinental connectivity, including the:

  • SEACOM submarine cable that terminates at the SEACOM Landing Station at Mtunzini (and is extended from there redundantly to the SANReN backbone node at Durban), and at the TENET router in Amsterdam;
  • West Africa Cable System (WACS) submarine cable that terminates at the SANReN backbone node in Cape Town and at TENET's router at Telecity, London. The WACS capacity available to TENET was procured by the CSIR on behalf of the DST in 2014 through the purchase from Broadband Infraco of approximately 8% of the cable system's capacity; and
  • South Atlantic Cable System (SACS) between Luanda, Angola and Fortaleza, Brazil. We reach SACS via the WACS system.

TENET’s SEACOM capacity was initially acquired in 2007 when TENET purchased the Indefeasible Right of Use (IRU) for the life of the cable, to a 10 Gbps circuit to London on the, then recently announced, SEACOM cable system. This capacity was increased to 60 Gbps in 2017 by means of a capacity swap.

Capacity on both the Eastern Africa Submarine Cable System (EASSy) and South Atlantic 3 (SAT-3/WACS) cable systems is also available via capacity swap arrangements.

TENET secures global interconnectivity through its own presence in London and Amsterdam, which includes membership of major Internet exchanges as well as transit contracts with two major providers. Traffic with other NRENs is exchanged through the London and Amsterdam gateways of the UbuntuNet Alliance. At these gateways, UbuntuNet has interconnections with the European research and education network, GÉANT (which connects 50 million users in over 10,000 institutions), and hence with other NRENs worldwide. TENET provides the UbuntuNet Alliance with some use of its commodity Internet connections in both cities.

Domestically, TENET maintains a presence at all three Teraco data centre sites and the associated NAPAfrica peering exchanges, from which it reaches major sources of inbound traffic through peering arrangements. TENET also maintains peering interconnections with most South African ISPs at ISPA’s Internet exchanges in Johannesburg, Cape Town and Durban.

TENET is a member of the South African Internet Service Providers Association (ISPA) and Wireless Access Providers’ Association (WAPA).

Collaboration with the SANReN Program

TENET collaborates systematically with the SANReN Competency Area (SCA), which is charged by the Department of Science and Technology (DST) with the deployment of SANReN. Under the terms of a Collaboration Agreement, the two organisations work together in growing the reach and capability of the South African NREN. In terms of this agreement, the SCA is primarily responsible for deploying infrastructure and for developing advanced services in collaboration with the beneficiary community, while TENET is primarily responsible for the operational management of the network and all the services delivered across it.