is available only to employees of the company that owns the equipment. Carriers also remotely access their servers to monitor and program their equipment. For even more reliability, some co-location facilities place redundant equipment at an additional co-location site. Leasing space in carrier hotels saves network providers the expense of establishing and maintaining the following: Physical security against break-ins Access to large amounts of power Access to backup power Backup generators Dual air conditioning systems Uninterrupted power supplies Backup fiber cabling to the facility Fire detection and fire suppression equipment Alarms to fire and police departments Staff members to plan and maintain the facilities Construction of earthquake-resistant facilities Carriers such as CenturyLink, AT&T, and Verizon have carrier-owned co-location facilities. These are generally in the same building as the carrier's Point of Presence (POP). Carriers offer a bundle of services at these facilities, including connections to routes connected to the co-location facility and connections to the carrier's POP, which is often located in the same building as the co-location services. AT&T and Verizon buy services from each other's co-location sites to reach www.TechnicalPDF.com customers whose locations are outside of areas in which they own access networks. Another type of co-location facility is a carrier-neutral facility. Neutral co-location facilities are owned by non- carrier organizations, including Equinix, Markley Group, and Telehouse. Neutral refers to the fact that carriers that use these facilities can send traffic over routes offered by any carrier connected to the same facility. A carrier at a neutral site can lease routes from any other provider at the site, such as Windstream or CenturyLink. Carriers locate gateways, switches, and routers in these facilities to exchange traffic with other providers and to manage their own traffic. Equinix provides data center services as well as co- location services. It is the lar