Neustar offers internal and external managed Domain name system (DNS) services that play a role in directing and managing traffic in the Internet, cloud-based DDoS attack protection and website performance management tools. Neustar manages the authoritative directories for the .us and .biz Internet domains, and acts as the worldwide "registry gateway" for China's .cn and Taiwan's .tw Internet domains outside of these two countries. Neustar also provides back end registry services for .co Top Level Domain. Neustar manages a collection of these directories that maintain addresses to direct, prioritize and manage Internet traffic, and find and resolve Internet queries and top-level domains on behalf of its enterprise customers. Neustar serves as the provider of registry services and manages directories of similar resources, or addresses, that its customers use for access and connectivity.