IP transit, peering and IXPs: how an operator carries your traffic

The Internet is not a single network: it is the interconnection of tens of thousands of independent networks, called autonomous systems (AS). For a packet to leave your premises and reach a server on the other side of the world, it crosses several of these networks. Understanding how they interconnect explains why some connections are fast and reliable… and others are not.

IP transit: buying access to the whole Internet

IP transit is the easiest service to grasp: an operator (the "transit provider") commits to carrying your traffic to any destination on the Internet, and to announcing your IP addresses to the rest of the world. You pay for that global reachability, usually by bandwidth (Mbps or Gbps) or by volume.

It is the fundamental building block of an Internet presence. Good transit is judged on three criteria: capacity (bandwidth available without congestion), latency (the quality and length of the routes) and redundancy (what happens if a link fails?).

Peering: exchanging directly, without a middleman

Peering means directly interconnecting two networks to exchange their mutual traffic, without going through a transit provider. Two hosting companies that exchange a lot of data have every interest in peering: the route becomes shorter, latency drops, and the exchanged traffic no longer costs transit.

Peering can be private (a dedicated link between two networks) or public, via an exchange point.

Internet exchange points (IXPs): the peering crossroads

An Internet exchange point (IXP, or IX) is a shared infrastructure — in practice one or more switches in a datacenter — where dozens or hundreds of networks connect to peer with each other. In France, France-IX in Paris and Marseille is the best-known example.

Connecting to an IXP lets you, with a single physical port, exchange traffic with a large number of networks at once. It is a powerful accelerator: more short routes, less dependence on a single transit provider, and greater resilience.

What it changes for you

An operator that combines quality transit, rich peering and a presence at IXPs gives you shorter routes to your users, lower latency and better fault tolerance. Conversely, a network that relies only on cheap, poorly interconnected transit will degrade your applications' experience — especially real-time use cases (voice, gaming, video, trading).

At Connect-IX we operate our own network core, with several Tbps of aggregate capacity and multiple interconnections, to deliver your traffic as close as possible to your users. That is exactly what our IP transit offering is built for, with native DDoS protection.