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What is an Internet Exchange?

The Beatles great Ringo Starr sang, “I get by with a little help from my friends.” Today’s global internet is a massive kumbaya of IT infrastructure friends of all kinds – multinational corporations, tech giants, government agencies, telco carriers, mobile networks, internet service providers (ISPs) and so on. But some pull their weight more than the others, providing the interconnectivity that enables efficient routing of local, regional and global data traffic. These important friends are Internet Exchange Points (IXP).

The Basics of Data Networks

First, some basics on data networks. Using agreed-upon networking protocols, data moving over networks is carried between network end points in data packets. Much like a piece of snail mail, packets contain the data needed for the application as well as data identifying the sender and the receiver. Billions of these packets traverse the planet every second. Whether the transport medium is a fiber optic cable, a satellite transmission or wireless network, an internet service provider (ISP) is tasked with the efficient exchange of packets between an originating end point and a destination.1

The speed at which these packets are delivered can have a huge impact on the performance of applications using the data. Each device (typically a router) that is used to move the data over the network is known as a hop. Just as the shortest distance between two points is a straight line, the fastest transfer of data occurs over the route with the fewest number of hops. 

Because it would be incredibly expensive and inefficient to have every ISP create direct connects with every other ISP, the Internet Exchange Point serves as a centralized hub for traffic for a specific geographic region and the exchange of traffic with other IXPs. 

What is an Internet Exchange Point?

An IXP is a physical location similar to a data center, where multiple ISPs and network operators interconnect their networks. By connecting to an IXP, each ISP can exchange traffic with all other ISPs that are connected to the IXP. These connections can be local, regional or international, depending on which ISPs participate.1

In addition to reducing costs and improving efficiency of network traffic, IXPs can also help to improve application performance by providing a more direct path for traffic between networks. This can result in faster and more reliable internet connections needed for mission-critical business applications.

IXPs are typically operated by neutral third-party organizations that provide the physical infrastructure and services necessary to facilitate the exchange of traffic between participating ISPs and network operators. Many large data center facilities are also IXPs. The Internet Exchange Map web site provides a fascinating look at where IXPs are located, down to the street level, with detailed information about which networks use them for peering.2 

MapDescription automatically generated
IXPs provide the interconnectivity that enables efficient routing of local, regional and global data traffic. This map shows only a fraction of the global distribution of IXPs that help provide the data routing throughout the internet in the Americas. Image courtesy of TeleGeography.

Packet Clearing House also provides a detailed repository of IXP locations, operators and networks. It lists more than 1,100 IXPs in its global database. The largest IXP in North America in terms of network participants is Any2 California, a CoreSite location in Los Angeles. It’s the connecting point facilitating much of Asia Pacific and North American internet traffic. More than 400 network operators and IT companies have operations in the facility.3

Peering Powers IXPs

When two or more networks connect to exchange data within an IXP, the process is referred to as peering. IXP peering is an important component of the internet infrastructure, as it helps to improve the performance, reliability and security of internet connections. 4

IXP peering refers to the process of exchanging internet traffic between two or more ISPs or network operators through IXP. In peering, ISPs and network operators agree to exchange traffic directly with each other, rather than routing traffic through a third-party network, such as a transit provider.

By connecting to an IXP, ISPs and network operators can establish direct peering relationships with other ISPs and network operators that are also connected to the IXP. This allows them to exchange traffic more efficiently and cost-effectively. Traffic within the local area network stays local, traffic outside the IXP location is routed efficiently.5

PeeringDB is another freely available database of networks, and source for interconnection data. The database facilitates the global interconnection of networks at internet IXPs, data centers and other interconnection facilities.

Types of IXPs

Not all IXPs are the same. Technically, only two network providers need to coordinate traffic to be an IXP but there are some basic types of IXPs in operation.6 They include:

  • Public IXPs: Public IXPs are open to all ISPs and network operators, regardless of their size or location. They typically provide a neutral and cost-effective platform for interconnecting networks and exchanging internet traffic. Many public IXPs are non-profit organizations with open membership.
  • Private IXPs: Private IXPs are operated by a single entity and are only accessible to a limited set of ISPs or network operators. 
  • Regional IXPs: Regional IXPs serve a specific geographic region, such as a city, state, or country, and are often used to improve the efficiency and performance of local internet traffic. 


Should You Care About IXPs?

In our personal lives, the role of an IXP is transparent. We can choose an ISP or a mobile provider based on its value or reputation, but we have no more control over the delivery of packets than we do the delivery of electricity. 

But what about for our businesses? Which friends should we depend on to help our business get by? For cloud services, third-party hosted applications, productivity applications and the like, performance should be part of standard service-level agreements. The big content delivery companies, such as Google, Amazon, Microsoft and others already have peering agreements with ISPs and IXPs. 

If you depend heavily on an on-premises data center and application performance, and response times are critical to your operation, an investigation of your current ISP’s peering arrangements can help you understand if you’re getting what you pay for, especially when it comes to application performance and its impact on user experience.

The physical location of your business – and your business partners and customers – are also a factor to consider. IXPs can be located anywhere, but the largest high traffic IXP locations are typically at the terminus of deep-sea fiber cables and in high-demand business areas – Los Angeles, Virginia/DC, Miami, Silicon Valley.1 So, for example, if your company is based in the U.S. but has branch offices in the Caribbean and South America, an IXP in Miami should be considered for your network traffic. 

Image showing the cover of CoreSite’s Ultimate Buyer’s Guide.
You can learn more about the impact interconnection has on your business in The Ultimate Interconnection Buyers Guide. No contact information required to download!

IXPs are the enabler of the internet, directing and routing traffic that is needed to drive our global economy by efficiently moving data across networks. Most of the time they are transparent, and individual business owners can trust traffic is being managed in their best interests in terms of cost and performance. But it helps to know how they work. 

A friend you can rely on, that has your back? That’s a friend indeed.

The CoreSite Team
Combining expertise, research and thought leadership to inform and advance hybrid IT.