Is It Really Worth to Peer At IXPs? A Comparative Study

Internet Exchange Points (IXPs) play a crucial role in the Internet ecosystem. However, existing literature fails in quantitatively assessing the advantage for an Internet Service Provider (ISP) to peer at an IXP. We give a contribution to bridge such a gap by collaborating with three medium-sized ISPs in Italy to compare key performance indicators (round-trip delay, hop count, packet loss, and jitter) as measured from several vantage points in presence and absence of IXP peerings. Our findings are that IXP-based paths exhibit better and more stable performance, whereas avoiding IXPs introduces performance deterioration and higher variability. Moreover, our measurements confirm that IXP-based paths tend to preserve the locality of traffic.