An Economic Side-Effect of Internet traffic engineering through “Prefix Deaggregation” technique

13 March 2012

Research carried out by Institute IMDEA Networks and University Carlos III of Madrid (UC3M) focuses on the economic side-effects of a particular traffic engineering tool widely used in the Internet and known as “prefix deaggregation”. This technique allows networks to experience a stabilization of their traffic on the transit links with their Internet providers.

---

The results of the study “An Economic Side-Effect for Prefix Deaggregation” reveal that this particular side-effect translates into a decrease of the transit traffic bill, which means savings for the networks deploying this type of mechanism for reasons related with optimizing the use of the network. This collateral benefit is non-negligible for current Internet networks, as traffic demands are permanently on the increase, both in terms of the quantity and the quality of the information transmitted.

 

The study is to be presented at the 7th Workshop on the Economics of Networks, Systems, and Computation Workshop (NetEcon 2012), collocated with IEEE INFOCOM 2012 – the premier conference in telecommunication and networking research – to be held in Orlando, USA between March 25th and 30th. The research work has been carried out by Andra Lutu and Rade Stanojević of Institute IMDEA Networks and by Marcelo Bagnulo, affiliated to UC3M, and an active collaborator with the Institute.

The Internet is the interconnection of over 36000 domains known as Autonomous Systems (ASes), which engage in dynamic relationships that interplay with their technical and economic necessities. The routing between ASes relies on the Border Gateway Protocol (BGP), which is responsible for the exchange of reachability information and the selection of paths according with the policies specified by each domain.

The way in which the traffic flows in the interdomain is influenced by the path dynamics triggered in the continuous evolution of the Internet topology and the routing policies of each network. Hence, individual network managers need to permanently adapt to the interdomain routing changes and, by engineering the Internet traffic, optimize the use of their network. One important task achieved through the use of traffic engineering tools is the control and optimization of the routing function in order to allow the ASes to shift the incoming and outgoing traffic in the most effective way.

The injection of more-specific prefixes through BGP represents a powerful traffic engineering tool, which offers a fine-grained method to control the interdomain ingress traffic. This technique implies that ASes selectively announce distinct fragments of their address block to different upstream providers. This type of phenomenon is commonly known as “prefix deaggreagation”.

Network economics is one of the main research areas at IMDEA Networks. Thus, the Institute actively generates knowledge on a topic of key socio-economic concern. This study examines one particular economic side-effect of deaggregation, namely the impact on the transit traffic bill. It concludes that the use of more-specific prefixes has a traffic stabilization side-effect which translates into a decrease of the transit traffic bill. This publication proposes an analytical model in order to quantify the impact of deaggregation on the transit costs, validating the results obtained by means of simulations and through the extensive analysis of real BGP routing information data.