14-18 March 2016
Hotel Novotel
Africa/Dakar timezone
Enabling Virtual Research and Education Communities

Accessibility of the Root Name Servers of the West African Countries

Not scheduled
Saly 1 (Hotel Novotel)

Saly 1

Hotel Novotel

Avenue Abdoulaye Fadiga, Dakar 18524, Senegal
Network Design and Operation


Dr Frédéric OUEDRAOGO (Université de Koudougou)


The accessibility of the Web pages relies on the services of the Domain Name System (DNS) through their servers around the world. The Domain Name System is a hierarchical distributed naming system for computers and network services. The main service of the DNS consists to translate the domain names using by humans to the numerical ip addresses needed for the purpose of computers and others services. The DNS play a key role in the control of the web users. It is often used to block the use of a target website. For instance, Turkey has used a false resolution of the DNS queries to block the famous social networks Twitter and Facebook out of its citizens. In this paper we evaluate the quality of the DNS service through the access to the root name servers of West African countries. Precisely, we measure the Round trip time (RTT) of icmp echo reply packets sent from two monitors to these servers. The RTT is the time for a packet to travel from a given source to a given destination, plus the time to back from the destination to the source. The RTT is an important value that takes part in the estimation of the quality of various network systems. From the iana database, we retrieve the root name servers ipv4 ad- dresses that have authority on the country top-level domains (ccTLDs) of Burkina, Benin, Cote-d'Ivoire, Ghana, Niger, Nigeria, Liberia, Sénégal Mali and Togo. From monitors located in Ouagadougou and Paris, We perform peri- odically the RTT measurement by sending at each two minutes an icmp echo resquest toward each DNS server. The monitor in Burkina Faso is inside the West Africa zone and the monitor in France outside this zone. Obviously, having a monitor in each West African country may provide more information but this measurement framework is out of our reach. We assume that the monitors from these two locations will give a representative overview of the accessibility of the concerned root name servers. Each country has at least four root name server, but most of them are hosted in foreign countries, precisely in other continents. For example, some countries (Liberia, Mali,...) have all their servers hosted by foreign countries but the majority hosts one or two of their root name servers. The mean of the RTTs of root name servers on a sample of 3 hours of measurement (about one hundred rounds) shows the time to access the root name servers hosted by their own countries is relatively high. We made the same observation with the two monitors, precisely this time is higher with the monitor located in Ouagadougou (700 milliseconds on average) than the one in Paris (200 milliseconds on average). However, the access to the root name servers hosted in foreign countries is better, 5 milliseconds for the monitor in Paris and 400 milliseconds for the one in Ouagadougou. The access to the services provided by the root name servers of West African Countries hosted by the owner is not efficient. It is particularly worse for requests coming from Burkina Faso. Despite the geographical proximity, a dns request coming from France has better access to root name servers hosted in West Africa than a re- quest coming from inside this zone. Beyond the accessibility of these dns servers, our observation shows how is the state of the Internet between West African countries.

Primary author

Dr Frédéric OUEDRAOGO (Université de Koudougou)


Mr Didier BASSOLE (Université Ouaga 1)

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