Index O

O

One-Time Passwords (OTPs), 330

Open Shortest Path First. See OSPF

Open Transport API, 244

Operating systems

fault-tolerant systems, 438

router, 235

vulnerability, 312

Optical Service Providers (OSPs), 546

Optical Storage Networks (OSNs), 400, 546

defined, 546

DWDM technology, 546

Optimization, 471–548

application, 519–35

bandwidth, 472–87

load-splitting/load-sharing, 502–19

protocol, 536–41

route, 580–82

routing, 473–74

storage, 542–46

summary, 547–48

system-level traffic, 487–502

OSI

Connection-Oriented Transport Service (COTS), 662, 664

directory service standard, 125–26

Management Information Service (MIS), 663

management structure, 663

OSI reference model, 17–19

Application Layer, 17

Data Link Layer, 18

defined, 17

illustrated, 17

IP and, 26–28

Network Layer, 18

Physical Layer, 18

in practice, 19

Presentation Layer, 18

Session Layer, 18

Transport Layer, 18

OSPF, 175–76, 187–204

addressing model, 202–3

adjacencies, 198–200

adjacencies on NBMA, 200–201

areas, 195–96

backbone, 196–97

background, 187

characteristics, 187

convergence, 202

defined, 187

deployment, 176

designated router, 201–2

EGP choice, 204

EIGRP vs., 177

field definitions, 188–90

full-mesh peering, 201

header formats, 188

hello packet, 189

hierarchical internetwork, 194

hierarchy and route summarization, 203

as link-state protocol, 193

LSAs, 190

message authentication, 192–93

metrics, 191

Multicast, 272–75

neighbor acquisition, 198

networks, 193

operation, 193–204

packet formats, 187–93

protocol stack, 193

routing hierarchy, 194–95

routing information, 197–98

routing resources/bandwidth partitioning, 203

scalability, 202–3

timers, 191–92

variable-length packets, 189

virtual links, 197

VLSM support, 192

Out-of-band management, 677–78

Output queuing, 233

Overlay model, 380–81