What is a network service provider (NSP)?

A network service provider (NSP), also known as a backbone provider, is a company that owns, operates and sells access to internet backbone infrastructure and services. NSPs' primary customers are other service providers, including internet service providers, which, in turn, sell internet access to businesses and consumers. Several NSPs also function as ISPs themselves.

NSPs build and maintain fiber optic cable and core routers -- the principal data routers -- that make up the internet. Their physical connections come together at internet exchange points, where regional ISPs can connect to an NSP backbone. These locations are also called peering points.

Not all NSPs are household names, but they are essential to modern networking. Their high-speed infrastructure and services support a downstream ecosystem that includes ISPs, wireless carriers and virtual network operators, while also providing the foundation for all commercial Internet Protocol services.

Examples of NSPs

Most regions of the globe have a handful of NSPs, although some regions have only one. The following companies are some of the world's top NSPs, listed in alphabetical order:

AT&T.
CenturyLink.
China Telecom.
Cogent.
Deutsche Telekom.
NTT Data.
Orange.
Tata Communications.
Verizon Business.

How network service providers work

An ISP can purchase wholesale bandwidth from an NSP. This provides connectivity for its customers, who then access the network through their ISP's last-mile infrastructure connecting to the NSP's backbone.

From there, the NSP routes all traffic and provides the infrastructure needed for network connectivity. The NSP builds, maintains and expands its infrastructure to meet traffic demands. The ISP is responsible for its own network, sales, marketing and customer service.

ISPs can also purchase other services from an NSP, such as cloud-based services or web hosting, that are sold to end customers under the ISP's brand name. This is a strategy known as white labeling.