The Internet is often described as a "network of networks" because it is not a single physical entity, but hundreds of thousands of interconnected networks linking hundreds of millions of computers around the world. As such, the Internet is international, decentralized, and comprised of networks and infrastructure largely owned and operated by private sector entities. As the Internet grows and becomes more pervasive in all aspects of modern society, the question of how it should be governed becomes more pressing. Currently, an important aspect of the Internet is governed by a private sector, international organization called the Internet Corporation for Assigned Names and Numbers (ICANN), which manages and oversees some of the critical technical underpinnings of the Internet such as the domain name system and Internet Protocol (IP) addressing. ICANN makes its policy decisions using a multistakeholder model of governance, in which a "bottom-up" collaborative process is open to all constituencies of Internet stakeholders. National governments have recognized an increasing stake in ICANN policy decisions, especially in cases where Internet policy intersects with national laws addressing such issues as intellectual property, privacy, law enforcement, and cybersecurity. Some governments around the world are advocating increased intergovernmental influence over the way the Internet is governed. For example, specific proposals have been advanced that would create an Internet governance entity within the United Nations (U.N.). Other governments (including the United States), as well as many other Internet stakeholders, oppose these proposals and argue that ICANN's multistakeholder model is the most appropriate way to govern the Internet. On May 14, 2013, H.R. 1580, which states that "it is the policy of the United States to preserve and advance the successful multistakeholder model that governs the Internet," was passed unanimously by the House. Currently, the U.S. government, through the National Telecommunications and Information Administration (NTIA) at the Department of Commerce, holds a "stewardship" role over the domain name system by virtue of a contractual relationship with ICANN. On March 14, 2014, NTIA announced its intention to transition its stewardship role and procedural authority over key domain name functions to the global Internet multistakeholder community. If a satisfactory transition can be achieved, NTIA will let its contract with ICANN expire on September 30, 2015. NTIA has stated that it will not accept any transition proposal that would replace the NTIA role with a government-led or an intergovernmental organization solution.