Quantifying the Effects of Circuitous Routes on the Latency of Intra-Africa Internet Traffic

I recently presented a paper titled 'Quantifying the Effects of Circuitous Routes on the Latency of Intra-Africa Internet Traffic: A Study of Research and Education Networks' at the AFRICOMM 2014 conference in Uganda (presentation slides here). The paper resulted from Internet performance experiments that involved tracing Internet routes from 5 African vantage points to 95 African university networks.

The study aimed at: 1) characterising the routes for Internet traffic exchanged among African networks, 2) evaluating the level of interconnectivity among Africa’s National Research and Education Networks (NRENs). Results from this study highlighted three important challenges about the African Internet topology. Firstly, that Africa's Internet Service Providers (ISPs) are sparsely inter-connected, with most of the networks not peering locally, but having direct domain level interconnections with top tier networks in Europe. Secondly, over 75% of Internet traffic exchanged between Africa's networks is routed through inter-continental links and European Internet exchange points such as Amsterdam, London, Lisbon, and Marseille. This results in unnecessarily longer physical paths, which result in much higher latencies. To put this into context, traffic exchanged between southern Africa networks (within 2,000km) but routed through London, covers a distance of roughly 30,000km, hence a round trip of about 60,000km.

The paper also highlighted that African traffic that follows inter-continental routes is characterised by latencies that more than double those of traffic exchanged within the continent . In the study, inter-continental traffic from Africa to African universities experienced an average round-trip time of 300 ms, while traffic exchange within the continent experienced an average round-trip time of only about 140 ms.

High latencies are particularly of concern for NRENs, where many education and collaboration oriented applications are used. High latency makes difficult the use of Internet-based collaborative tools , such as video conferencing. Incidentally, the keynote speaker at the conference was Dr Francis Tusubira CEO of the UbuntuNet, an alliance of NRENs in east and southern Africa. In his address, he highlighted how the UbuntuNet Alliance is working to improve interconnectivity through the AfricaConnect Project currently under way. The AfricaConnect project aims to establish a dedicated cross-border backbone network linking NRENs in the alliance.

Other presentations covered aspects of wireless mesh networks and TV White Spaces (TVWS), and their use in rural/developing areas, as well as on network management in multi-carrier transmission networks, for enabling broadband connectivity in rural and remote regions.

The AFRICOMM 2014 conference took place from 24th to 25th November 2014 at Makerere University in Uganda. (AFRICOMM is an annual research conference organised by the European Alliance for Innovation (EAI), and is focussed on research related to e-Governance, e-Infrastructure, and e-Business in developing countries).