Internet Exchange Points (IxPs)

- Internet Exchange Points

 An Internet exchange point (IxP) is a physical location through which Internet infrastructure companies such as Internet Service Providers (ISPs) and Content Delivery Networks (CDNs) exchange Internet traffic between their networks (autonomous systems). At its core, an IxP is essentially a data center containing network switches that route traffic between the different member companies that share the costs of maintaining the physical infrastructure.

These locations exist on the “edge” of different networks, and allow network providers to share transit outside their own network. By having a presence inside of an IxP location, companies are able to shorten their path to the transit coming from other participating networks, thereby reducing latency, improving round-trip time, and potentially reducing costs. Without IxPs, traffic going from one network to another would potentially rely on an intermediary network to carry the traffic from source to destination. 

Across an IxP's local network, different providers are able to create one-to-one connections using the BGP protocol. This protocol was created to allow disparate networks to announce their IP addresses to each other plus the IP addresses that they have provided connectivity to downstream (i.e. their customers). Once two networks set up a BGP session, their respective routes are exchanged and traffic can flow directly between them.

IxPs fall roughly into five categories: non-profit organization, an association of ISPs, operator-neutral for-profit company, university or gov agency, or an informal association of networks.

Internet Exchange Points Map: It provides information for active Internet exchanges and buildings worldwide. They are integral part of the Internet ecosystem. 

- Function - IxP

IxPs are now well recognized as a vital part of the Internet Ecosystem and essential for facilitating a robust ICT sector.

The primary purpose of an IxP is to allow networks to interconnect directly, via the exchange, rather than through one or more third-party networks. The advantages of the direct interconnection are numerous, but the primary reasons are cost, latency, and bandwidth. 

Traffic passing through an exchange is typically not billed by any party, whereas traffic to an ISP's upstream provider is. The direct interconnection, often located in the same city as both networks, avoids the need for data to travel to other cities (potentially on other continents) to get from one network to another, thus reducing latency. 

The third advantage, speed, is most noticeable in areas that have poorly developed long-distance connections. ISPs in these regions might have to pay between 10 or 100 times more for data transport than ISPs in North America, Europe or Japan. Therefore, these ISPs typically have slower, more limited connections to the rest of the Internet. However, a connection to a local IxP may allow them to transfer data without limit, and without cost, vastly improving the bandwidth between customers of the two adjacent ISPs.

- Operation - IxP

A typical IxP consists of one or more network switches, to which each of the participating ISPs connect. 

All Ethernet port speeds are to be found at modern IxPs, ranging from 10 Mbit/s ports in use in small developing-country to ganged 10 Gbit/s ports (or ports with 100 Gbit/s are available) in major centers like New York, London, Frankfurt, Amsterdam, and Palo Alto. 

Please refer to "Carrier Ethernet and Networking Services" for more details.

[More to come ...]