Cisco Network Convergence System (NCS) 520 are next-generation Layer 2 customer-located devices and network demarcation devices for service providers. These 10 Gigabit Ethernet demarcation points redefine the demarcation between the customer LAN and a service provider's mobile and cloud applications. They provide standards-based demarcation as defined by the Metro Ethernet Forum (MEF) for services such as Ethernet point-to-point line (ELINE) and Ethernet multipoint-to-multipoint (ELAN) services, with advanced clocking and Quality of Service (QoS).