Cisco ESR10008 Hardware Installation Guide - Page 159

Glossary Multiplexing An activity in which multiple logical signals are transmitted simultaneously across a single physical channel. Multiprotocol Label See MPLS. Switching N NEBS Network Equipment Building Systems. The Telcordia (formerly Bellcore) requirements for equipment deployed in a central office environment. Covers spatial, hardware, crafts person interface, thermal, fire resistance, handling and transportation, earthquake and vibration, airborne contaminants, grounding, acoustical noise, illumination, EMC, and ESD requirements. Network Equipment See NEBS. Building Systems Network termination unit See NTU. Nonvolatile RAM See NVRAM. NTU Network terminating unit. The network equipment that connects directly to the data terminal equipment. NVRAM Nonvolatile RAM. RAM that retains its contents when a unit is powered off. O OC Optical carrier. A series of physical protocols (OC-1, OC-2, OC-3, and so forth), defined for SONET optical signal transmissions. OC signal levels put STS frames onto fiber-optic lines at a variety of speeds. The base rate is 51.84 Mbps (OC-1); each signal level thereafter operates at a speed divisible by that number (thus, OC-3 runs at 155.52 Mbps). ODL Optical data link. OIR Online insertion and removal. Feature that permits the addition, replacement, or removal of cards without interrupting the system power, entering console commands, or causing other software or interfaces to shut down. Same as hot swapping. Online insertion and See OIR. removal Optical carrier See OC. Optical fiber See Fiber-optic cable. OL-0659-13 Cisco 10008 Router Hardware Installation Guide GL-9