Uptime Institute or TIA. For service organizations today, SSAE 16 calls for a description of its "system". This is far more detailed and comprehensive than SAS 70's description of "controls". Other data center compliance standards include Health Insurance Portability and Accountability Act (HIPAA) audit and PCI DSS Standards. Power Colocation facilities generally have generators that start automatically when utility power fails, usually running on diesel fuel. These generators may have varying levels of redundancy, depending on how the facility is built. Generators do not start instantaneously, so colocation facilities usually have battery backup systems. In many facilities, the operator of the facility provides large inverters to provide AC power from the batteries. In other cases, customers may install smaller UPSes in their racks. Some customers choose to use equipment that is powered directly by 48 VDC (nominal) battery banks. This may provide better energy efficiency, and may reduce the number of parts that can fail, though the reduced voltage greatly increases necessary current, and thus the size (and cost) of power delivery wiring. An alternative to batteries is a motor–generator connected to a flywheel and diesel engine. Many colocation facilities can provide redundant, A and B power feeds to customer equipment, and high end servers and telecommunications equipment often can have two power supplies installed. Colocation facilities are sometimes connected to multiple sections of the utility power grid for additional reliability. Internal connections Colocation facility owners have differing rules regarding cross-connects between their customers, some of whom may be carriers. These rules may allow customers to run such connections at no charge, or allow customers to order such connections for a monthly fee. They may allow customers to order cross-connects to carriers, but not to other customers. Some colocation centres feature a "meet-me-room" where the different carriers housed in the centre can efficiently exchange data. Most peering points sit in colocation centres and because of the high concentration of servers inside larger colocation centres, most carriers will be interested in bringing direct connections to such buildings. In many cases, there will be a larger Internet exchange point hosted inside a colocation centre, where customers can connect for peering. See also Carrier-neutral data center Direct market access References External links Build Or Colocate? The ROI Of Your Next Data Center Multi-Tenant Datacenter Global Providers – 2014 DCK Guide To Modular Data Centers: The Modular Market Data centers Internet architecture Internet hosting