A Brief Guide To Internet Exchange Points – An Internet Exchange Point or IXP as they are abbreviated to is an actual physical location where Internet Service Providers (ISPs) and Content Delivery Networks (CDNs) connect with one another. They exist on the very edge of various different networks and enable the providers of networks to transit both inside and outside of their own network. This means that by being inside of an IXP location, such as Euqinix LD4, a company is able to shorten the distance they need to transit to and from other participating networks. This works to not only improve the time of a round trip and minimize latency, but also reduce costs in some instances.
How Does An IXP Work?
On a basic level, an IXP is a physical location that contains switches for networks that work to route traffic amongst the different networks that are members. Using a range of methods, the networks distribute the expense of managing and maintaining the infrastructure and services associated with running these between them.
On a more technical level, an IXP is an extensive double layer Local Area Network (LAN) that is built with a number of Ethernet switches that are all connected with one another either across a single physical location or across various different buildings. Therefore, at its most basic, an IXP is not that much more different from a network that you may have in your own home – the only difference is the sheer size and scale of it.
During the past generation, the level of expansion that has happened in network interconnections has been enormous, seeing the building of various facilities for housing data centres.
Why Are IXPs Important?
Without the use of an IXP, any traffic that is trying to get from one network to another would solely rely on a network intermediary in order to carry traffic from the source through to the destination. These networks are known as transit providers. Whilst in some situations they work completely fine, it is very costly to maintain a direct connection with every single ISP that there is in the world.
Putting so much reliance on an ISP to be the carrier of all local traffic can negatively impact upon performance. Where this happens, it leads to a situation that is known as tromboning – traffic from one location to another within the same city or country, travels vast distances in order to be exchanged and then returned back to its desired destination.
IXP Vs. PNI Interconnection
Where there are two networks and these are considered to have important traffic, it may be the case that they wish to move away from having a shared infrastructure under an IXP and instead prefer to go with having dedicated interconnectivity with one another. This is where a Private Network Interconnect or PNI is useful. This works to connect any port that is on one of the two networks with a single port on the other network. The Border Gateway Protocol (BGP) is the same here as with an IXP that has a shared peering setup.