Port Translation nontrunked radio, 315 (NAPT), 442 nonzero dispersion-shifted fiber Network Address Translation (NAT), 442 (NZDSF), 404, 417 Network Control Protocol (NCP), 430 Nortel Networks, 10, 209, 213, 215, 218, network element layer (TMN), 221 262, 297, 470, 472 network integrity, 45 North American Digital Hierarchy, network interface cards (NICs), 257-258 173, 174 network interface devices (NIDs), 234 NRT-UBR service (ATM), 239 Network Layer (OSI model), 60, 101-112 NSFNET, 39, 40, 431 responsibilities of, 101, 106 NSI (Network Solutions, Inc.), 434 routing protocols, 105-112 numbering plan area (NPA), 145, 146 network management layer (TMN), 222 NYNEX, 140 network operating systems (NOSs), 257 Nyquist, Harry, 28, 202 network value hierarchy, 477-479 networks, 14-15 (See also Internet) access, 15-18 bandwidth in, 381 cable, 304-309 OAM&P, 178 cellular, 317-318 Oberst, Lee, 128 connectionless, 94, 98-100, 373 Object Management Group, 222 connection-oriented, 94, 96-98, Open Shortest Path First (OSPF), 109 372-373 Open Systems Interconnection data communications, 45-49 Reference Model (see OSI Model) Index operating systems (OS), computers, 244, 248-250 operations support systems, 234 Pacific Bell, 140 operator systems, 234 packet discard, III optical carrier level (OC), 183 packet switching, 92-93, 96, 372-373 optical character recognition (OCR), 270 connectionless networks, 98-100 optical fiber ring, 164, 165 connection-oriented networks, 96-98 optical fibers, 397-402 SS7, 146-147 modes, 413-417 X.25, 256 nonlinearities, 404-406 packets, 53 optical networks, 370-371, 393-418 pair gain, 288 early breakthroughs, 394-395 Panasonic, 310, 474 light sources, 396-397 parallel bus, 16, 17. 244, 251-252 noise with, 32 Parsons, Ed, 303 nonlinearities, 404-406 passive RFID systems, 340 optical amplification, 408-412 Path Overhead, 180, 181, 183, 186, 195 optical fibers, 397-402, 413-418 payload channelization 192 receivers, 412-413 payload (SONET), 181, 183, 187 regenerators in, 200 PBX equipment, 214-215, 287-289 s