See intrachannel crosstalk coherent detection, 263-265 idea behind, 263 improved receiver sensitivities, 264 coherent receivers, 263-265 advantages, 265.
Trang 1bidirectional protection switching (continued)
illustrated, 541
See also protection switching
bidirectional systems, 303-305
direction illustration, 305
illustrated, 304
wavelengths, 304
bidirectional WDM systems, 686-688
amplifiers for, 688
asymmetric traffic and, 687
designing, 688
guard band, 688
illustrated, 686
implementation using, 687
unidirectional comparison, 686-688
birefringence, 57
bit error rates (BERs), 258-263, 264-265, 276
evaluating, 260
floor, 268,269
for high-speed optical communication
systems, 250 impairments and, 284
measurement, 277, 509
for OOK direct detection receiver, 276
threshold setting and, 260
of uncoded system, 278
bit interleaved parity (BIP) code, 268
bit interleaving, 620-623
demultiplexing operation, 622-623
function illustration, 621
optical multiplexer, 622
bit rate, 29
aggregate, 604
bandwidth ratio, 30
distance product, 53, 54
four-wave mixing and, 90-91
maximum, 348
RZ/NRZ transmission and, 312
sensitivity as function of, 261
transparency, 420
bit stuffing, 274
blazed reflection gratings, 121,122, 227
blazing, 121
blocking model, 465,467-474
blocking probability, 467
computing, for lightpath requests, 470
conversion gain, 472, 473
Erlang-B formula and, 468
estimating, 467
full wavelength conversion and, 471,472 reduction, 468
blocking switches, 202 border gateway protocol (BGP), 392 Bragg gratings, 123-126
apodization, 124, 126 bandwidth, 126 fiber, 127 formation, 123 index distribution, 124 principle of operation, 124-126 reflection spectra, 125 uses, 123
See also gratings Bragg wavelength, 124 Brillouin gain coefficient, 325 Bronze service class, 567
BT Labs testbed, 654
bubble-based waveguide switches, 212, 213 buffering, 618, 635-649
implemented with feedback delay lines, 640 input, 635, 639
lack of good methods, 636
output, 637-639
recirculation, 639-641 bulk mechanical switches, 207-209 bulk micromachining, 211,212 burst switching, 649-650
cable network, 595
capital cost, 668 carriers capital cost, 668 long-haul, 688 metro, 699
new generation of, 668
operations cost, 668
scalable networks and, 669
SONET/SDH-based backbone network, 670 carriers carrier, 9
cascaded filters, 307-308 C-band, 66
chromatic dispersion in, 98 EDFAs in, 289
L-band vs., 689
long-haul networks, 689 See also L-band center frequency, 732 central office, 593
Trang 2channel spacing, 29, 336
FWM and, 91,332
increased, 332
unequal, 332, 347
chirped fiber Bragg gratings, 316-318
for compensating three wavelengths, 318
illustrated, 317
large chromatic dispersion, 317
uses, 317
See also dispersion compensation
chirped Gaussian pulses, 69-74, 104, 356
broadening of, 70-74
illustrated, 70
propagation, 734-735
See also chromatic dispersion
chirped RZ modulation, 343
chirp factor, 70
chirp RZ pulses, 100
chromatic dispersion, 36, 57, 68-76
absence of, 69
anomalous, 69
causes of, 309
in C-band, 98
chirped Gaussian pulses, 69-74
compensation, 38,267, 343
DM soliton systems, 341
for DSF, 331
EDFAs and, 38
fiber nonlinearities trade-off, 38, 49
length, 71, 72
management, 335
map, 315
material dispersion, 68, 69
nonzero-dispersion fiber (NZ-DSF),
93,316
normal, 69
origin, 57, 58
parameter, 74
profiles, 74-76, 309
pulse-broadening effect, 70, 71
pulse compression effect, 72, 73
reasons for, 68
slope, 75,343
slope, compensation, 318
for SMF, 331
system limitations, 72
total, 74, 315
total, variation of, 319
waveguide dispersion, 68
chromatic dispersion limits communication link length, 312 large source spectral width, 313-314 narrow source spectral width, 309-311 NRZ modulation, 309-311
RZ modulation, 311-314 for unchirped pulses, 312, 313 circuit emulation, 675
circuit-switched networks, 6-7 problem, 7
services, 7 circulators, 113 cladding, 33 electric/magnetic field vectors in, 59 materials, 50
refractive index, 60 Class I safety standard, 527, 530 Class IIIa safety standard, 527 Class IIIb safety standard, 527 client layers, 363-400 ATM, 363,381-388 ESCON, 363 Fibre Channel, 363 Gigabit Ethernet, 363
IP, 363, 388-395 protection, 563 SONET/SDH, 363, 364-381 types of, 363
clients, 403,404 clipping, 244-245 probability, 245
of subcarrier modulated signal, 244 clock, 251
clock recovery, 251,273 closest-to-finish, 648 Clos switch, 204-205 advantages, 205 illustrated, 205 three-stage, 204 coding gain, 269-270
of FEC code, 269 Reed-Solomon codes, 270 repetition code, 269-270 coherent crosstalk See intrachannel crosstalk coherent detection, 263-265
idea behind, 263 improved receiver sensitivities, 264 coherent receivers, 263-265
advantages, 265
Trang 3coherent receivers (continued)
balanced, 278
heterodyne, 264
homodyne, 264
illustrated, 264
sensitivity, 265
in WDM system, 265
common object request broker (CORBA)
model, 501
competitive LECs (CLECs), 4
compliant wavelength interface, 525
conduction band, 161
configuration management, 496, 519-526
adaptation management, 524-526
connection management, 520-524
equipment management, 519-520
See also network management
congestion, 450, 454
connectionless services, 6, 8
connection management, 496, 520-524, 531
interaction with other layers, 522-524
interoperability, 520
route computation, 521-522
signaling network, 522
signaling protocol, 522
topology management, 521
See also configuration management; network
management connection-oriented services, 6
constant bit rate (CBR), 387
contention resolution
by delay lines, 656
optics (CRO), 657
recirculation buffering and, 640
wavelengths for, 641-645
Contention Resolution by Delay Lines (CORD)
testbed, 656-657 conversion gain, 472,473
core, 33
electric/magnetic field vectors in, 59
materials, 50
multimode fiber, 33
single-mode fiber, 35
coupled mode theory, 110
couplers, 108-112
2 • 2, 108, 112, 226
in AWG, 142
conservation of energy, 111-112
coupling ratio, 136
illustrated, 108
lossless, 111 power transfer function, 110 principle of operation, 110-111 star, 108-109
uses, 109 wavelength-independent, 108-109 wavelength-selective, 108 coupling coefficient, 110 crossbar switch, 203-204 architecture, 203 fabrication, 204 illustrated, 204 cross-gain modulation (CGM), 219-220 advantages, 220
cross-phase modulation vs., 220-221 pulse distortion in, 220
SOA gain dependencies and, 219 cross-phase modulation (CPM), 83, 89-90, 220-223,323, 333
CGM vs., 220-221 effect in WDM systems, 90 illustrated, 221
intensity modulation conversion, 220 nonlinear dielectric polarization, 89 properties, 220
reducing, 90
in WDM systems, 90, 335, 338
See also nonlinear effects crosstalk, 165,299-308
in all-optical networks, 345 bidirectional systems, 303-305 forms of, 299
interchannel, 299 intrachannel, 299-301 Mach-Zehnder interferometers and, 137
in networks, 303 Raman amplifiers, 161 reducing, 165, 305-307
in SOAs, 165
of switches, 201
uses, 165 cutoff wavelength, 60, 192-193, 194 data communication network (DCN), 498, 512-513
realization methods, 513 signaling and, 512-513 transport methods, 512 datagram services, 8, 19 data link layers, 18-19, 382, 388
Trang 4DBR lasers, 181-183
sampled grating (SG), 183, 184-185
super-structure grating (SSG), 183, 184-185
two- and three-section, 181-183
See also lasers
DC balance, 241
deadlock, 649
decision rules, 258
dedicated bandwidth, 594
dedicated protection, 540
defect condition, 510
defect indicators, 510-511
deflection index, 648
deflection routing, 637, 645-649
delay, 645-647
livelock, 649
small buffers, 649
throughput, 647-648
deflection rules, 648
degeneracy factor, 92
degree constraints, 451
delay, 645-647
differential group (DGD), 62, 320, 321
propagation, 647
queuing, 647
delay lines
contention resolution by, 656
feedback, 636, 640
feed-forward, 636
required for different
architectures, 644
demodulation, 239, 250-267
APD noise, 255
bit error rates, 258-263
coherent detection, 263-265
direct detection receiver, 253-254
equalization, 266-267
front-end amplifier noise, 254-255
ideal receiver, 252-253
optical preamplifiers, 255-258
as "photon counting," 252
timing recovery, 265-266
See also modulation
demultiplexers, 115
AWG as, 140
with broad passband, 150
cost reduction, 365
misalignment, 345
MZI as, 137
optical packet, 659
depletion region, 163 design considerations, 341-348 all-optical networks, 345-346 dispersion compensation, 343
DM soliton systems, 338-341 fiber type, 341-342
interchannel spacing and number of wavelengths, 344-345
modulation, 343 nonlinearities, 323-335, 344 overall, 341-348
soliton systems, 336-338 transmit power and amplifier spacing, 342-343 transparency, 348 wavelength planning, 346-347 wavelength stabilization, 335-336 detectors, 192-199
front-end amplifier, 192, 197-199 photodetector, 192-197
dial up bandwidth, 521 dichroics, 113-114 dielectric, 63 dielectric polarization, 56, 82 linear, 82
nonlinear, 83, 84, 85, 89, 91 dielectric thin-film filter, 133-135 multiplexer/demultiplexer using, 135 TFF, 133
TFMF, 133, 135 three-cavity, 134 transfer functions, 134 dielectric waveguides, 63-64 differential group delay (DGD), 62, 320 average, 320
variation with time, 321 differential loss, 641 diffraction, 55, 117, 120 diffraction gratings, 120 diffraction pattern, 122-123 amplitude distribution, 123 intensity distribution, 123 Diff-Serv, 392
digital crossconnects (DCSs), 22, 380-381 ADM functions, 381
narrowband, 380 ports, 380 types of, 381 uses, 380 wideband, 380
Trang 5digital subscriber loop (DSL), 591,597
modems, 597
technology, 11
digital wrapper overhead, 518-519
advantages/disadvantages, 519
uses, 519
See also optical layer overhead
Dijkstra shortest-path-first algorithm, 391,581
dimensioning models, 464-482
maximum load, 475-482
statistical, 464-4 74
direct detection, 252
direct detection receiver, 253-254,
265,273 BER for, 276
pin, 285
directional couplers, 108
direct modulation, 38, 186-187
advantages, 187
disadvantages, 187
illustrated, 187
with NRZ systems, 343
See also modulation
dispersion, 35, 49, 68, 308-323
chromatic, 36, 57, 68-76, 309
as cumulative effect, 308
forms of, 308
group velocity (GVD), 69, 731,733
importance, 101
intermodal, 35, 36, 52, 308
as limiting factor, 49
management, 314
material, 68, 69
polarization-mode (PMD), 62, 308, 320-323
waveguide, 60, 68, 69
See also chromatic dispersion
dispersion compensating fibers (DCFs), 267,
315-316 disadvantages, 315-316
figure of merit (FOM), 316
total chromatic dispersion, 315
dispersion compensation, 314-319
chirped fiber Bragg gratings, 316-318
with DCFs, 267, 315-316
design considerations, 343
for each channel separately, 319
methods, 314
PMD, 321-322
slope, 318-319
dispersion fibers negative, 95-98 positive, 95-98 dispersion-managed solitons, 100-101,240 average chromatic dispersion, 341 average span dispersion, 339 constant BER contours, 340 peak transmit power, 339 performance comparison, 341 performance factors, 340 spans between amplifiers, 338 system design, 338-341 use of, 338
See also solitons dispersion parameter, 312 dispersion-shifted fibers (DSF), 75 chromatic dispersion for, 331 four-wave mixing (FWM) and, 331 WDM systems and, 684
distributed-feedback (DFB) lasers, 37, 169-171,224
advantages, 170 array of, 186 packaging, 170 reflections into, 170 SLM, 310
structure, 169 temperature sensitivity, 170
See also lasers distributed network control, 496
distribution networks, 593
double sideband (DSB) signals, 248 drop-and-continue function, 502, 556 dual homing, 556-558
deployment, 558 hub nodes, 556 illustrated, 557 duobinary modulation See optical duobinary modulation
dynamic WXCs, 116 edge-emitting lasers, 173 effective cross-sectional area, 78-79 effective index, 60, 68, 69
effective length, 78-79, 88
in amplified systems, 323-325 calculation, 78
as function of link length, 324 reducing, 324
Trang 6electric flux density, 56
electro-absorption (EA)modulators, 188
electronic regeneration, 25
electronic switches, 215-216
electro-optic switches, 213-214
element management system (EMS),
497-499, 512
communication, 498, 499
multiple, 498
views, 498-499
See also network elements; network
management
enhanced HFC, 598-599
architecture, 598
bandwidth, 598
bandwidth allocation, 599
evolution path, 599
See also access networks
equalization
electronic, 267, 273
gain, in EDFAs, 292-293
introducing at amplifier stages, 292
for PMD compensation, 321
structures, 266-267
equalization filter, 266-267
effect of, 267
illustrated, 267
equalizers, 251
equipment management, 519-520
deployment, 520
design, 519
inventory maintenance, 520
See also configuration management; network
management
erbium-doped fiber amplifiers (EDFAs), 37,
154-159, 224
advantages, 37, 289
bandwidth, 66
C-band, 289
chromatic dispersion and, 38
elements, 154
energy levels, 155
gain bandwidth, 289
gain equalization in, 292-293
gain flatness, 156-158
gain saturation in, 290-291
high input powers and, 290
illustrated, 154
L-band, 158-159, 289, 292
multistage designs, 158 nonflat gain spectrum, 38 passband flatness, 292 principle of operation, 154-156 pump, 517
Raman amplifiers vs., 159 SOAs vs., 161
two-stage, 158
in WDM communication systems, 157
See also optical amplifiers erbium-doped fluoride fiber amplifiers
(EDFFAs), 157
Erlang-B formula, 468 error-correcting codes, 267, 273 Reed-Solomon codes, 270-272 repetition code, 269
error detection, 267-272 error propagation, 247 ESCON (enterprise serial connection) network,
12, 21,363,396-397, 400 data rate per channel, 396 limiting factors, 397 maximum interconnection distance and, 397
protocol throughput, 503 standards, 724-725 etalons, 118
Ethernet, 398 10-Gigabit, 389, 398 Gigabit, 363,389, 398
excessive loss, 110 excess noise factor, 255,275
excited state absorption, 157
expedited forwarding (EF) packets, 392 external cavity lasers, 171-172 disadvantages, 172 with fiber Bragg grating, 172 grating, 171, 172
structure, 171 tunable, 179-180
See also lasers external modulation, 38, 187-190 with DFB lasers, 314 lithium niobate, 188, 189, 190 for long-distance transmission, 311 semiconductor electro-absorption (EA), 188
types, 187-188
See also modulation
Trang 7extinction ratio, 186,
200, 287-288 chirp reduction and, 310
power penalty, 288
reducing, 288
extra traffic, 546
eye diagram, 251
Fabry-Perot amplifier, 167
Fabry-Perot cavity, 167
Fabry-Perot filter, 227
power transfer function, 131,132
tuning, 133
Fabry-Perot (FP) laser, 168
array, 186
oscillation, 168
failures
active component, 538
causes, 538
erroneous connections due to, 556
events, 538
human error, 538
IP network, 559
mean time between, 538
node, 538,553-554
simultaneous transmitter, 562
slow recovery from, 558
in TPONs, 604
See also protection
Faraday rotator, 114
fast signaling channel, 498
fault management, 496, 507-519
alarm management, 510-512
example, 507
optical trace, 509
service restoration, 507
support, 503
See also network management
feedback delay line architecture, 640
feedback shift register, 275
feed-forward delay line architecture,
636, 640 fiber Bragg gratings, 127
chirped, 316-318
external cavity lasers with, 172
optical add/drop elements, 128
temperature coefficient, 127
uses, 127
fiber cables, 11
fiber distributed data interface (FDDI), 39, 241
fiber gratings, 126-133 fiber, 127
long-period, 127-132 photosensitivity, 126 short-period, 126-127 tunability, 133
See also gratings fiber lasers, 166 fiber modes, 59-61 effective index, 60 fundamental, 59 propagation constant, 59 fiber nonlinearities See nonlinear effects fiber to the building (FTTB), 600
fiber to the cabinet (FTTCab), 600 fiber to the curb (FTTC), 40,
592, 599-609 architecture, 600 feeder network, 600 optical network units (ONUs), 599-607
See also access networks fiber to the home (FTTH), 40, 599 fiber transmission technology, 11 Fibre Channel, 363,397 open fiber control (OFC) protocol, 528-530, 534 standards, 724-725 field-effect transistor (FET), 199 figure of merit (FOM), 316
filters, 115
acousto-optic tunable (AOTFs), 143-147, 230
applications, 116 cascaded, 307-308 dielectric thin-film, 133-135 equalization, 266-267 Fabry-Perot, 131,133,227 guiding, 337, 338 multilayer thin-film, 743-750 piezoelectric, 133
sliding-frequency guiding, 338 technology characteristics, 116-117 thin-film resonant cavity (TFF), 133
thin-film resonant multicavity (TFMF),
133, 135 transversal, 267 finite field, 271 first-order PMD, 322 first-passage model, 464-465,466
Trang 8fixed-wavelength conversion, 457
ring network with, 479
WA problem and, 459
flooding, 390-391
forward defect indicator (FDI) signal,
510-512
forward error correction (FEC), 268, 505
code performance measurement, 269
coding gain, 270
reasons for using, 268
in undersea transmission systems, 271
use of, 269
forwarding, 618
Fourier transforms, 55, 82, 728,732
four-wave mixing (FWM), 38, 76, 90-93, 104,
223-224, 323,329-333
advantages, 223
bit rate and, 90-91
channel spacing and, 91
dispersion-shifted fiber (DSF)
and, 331
effect, 329
efficiencies, 331
illustrated, 224
intrachannel crosstalk manifestation, 331
limit computation, 356
maximum transmit power limitation, 332
nonlinear dielectric polarization, 91, 92
power enhancement, 223
power penalty, 330
in WDM systems, 332
See also nonlinear effects
frame relay, 8
framing pulses, 620
Franz-Keldysh effect, 190
free spectral range (FSR), 132, 228
of AWG, 141
input/output waveguides and, 228
frequencies
equal spacing, 346
microwave, 243,244
optical carrier, 242
frequency division multiplexing (FDM), 13
front-end amplifiers, 192, 197-199, 250
dynamic range, 198-199
equivalent circuits, 198
high-impedance, 197, 198, 199
noise, 254-255
transimpedance, 197, 198, 199
types of, 197
FRONTIERNET switch, 652-654 illustrated, 653
wavelength converters, 652
See also PPS testbeds full service, 592 full service access network standard, 604 full wavelength conversion, 457 blocking probability and, 471,472 ring network with, 478
WA problem and, 459 wavelength-routing networks, 464 full width half maximum (FWHM), 132, 145 fundamental mode, 59
fundamental solitons, 98, 739 pulse, 739
pulse illustration, 99
See also solitons gain
amplifier cascades, 294 APD receivers, 260 clamping, 297 coding, 269-270 conversion, 472,473 EDFA, bandwidth, 289 equalization, in EDFAs, 292-293 FEC coding, 270
mode-locked lasers, 176 Reed-Solomon codes, 270 repetition code, 269-270 SBS, 79, 325, 326 SOA dependencies, 219 SRS bandwidth, 327 SRS coefficient, 81 unequal, effect of, 293 gain saturation
in EDFAs, 290-291 optical amplifier illustration, 291 Gaussian distribution, 752-753 Gaussian random process, 756 geometrical optics approach, 50-55 intermodal dispersion and, 53 light propagation, 51 geometrical optics model, 33
illustrated, 35 light rays, 33 get operation, 500 Gigabit Ethernet, 363,389, 398
Gold service class, 567 Gordon-Haus jitter, 337
Trang 9graded-index fibers, 53, 54
graph coloring, 461-462
grating circle, 142
grating coupler sampled reflector (GCSR)
lasers, 183, 185 illustrated, 186
VGF, 185
grating equation, 121
grating external cavity lasers, 171
grating plane, 120
gratings, 118-122
apodized, 124
arrayed waveguide (AWG), 137,
139-143,606 Bragg, 123-126
diffraction, 120
examples, 119
fiber, 126-133
order, 121
pitch, 120, 121
principle of operation, 121-122
reflection, 119, 120
Stimax, 120
transmission, 119, 120
very long, 318
greedy algorithm, 476-477
grooming, 440
group velocity, 69, 731
dispersion (GVD), 69, 731,733
of pulse, 732
guaranteed bandwidth service, 655
guided rays, 52
guidelines for description of managed objects
(GDMO), 501 guiding filters, 337-338
center frequency, 337
sliding-frequency, 338
half-wave plate, 114
head end, 593
header processing, 634-635
head-of-line (HOL) blocking, 639
helical LAN (HLAN) topology, 655
heterodyne receivers, 264
heterostructure, 163
high channel count multiplexer architectures,
148-151 multistage banding, 148-149
serial approaches, 148
single-stage, 148
higher-order nonlinear susceptibility, 741 higher-order solitons, 100
high-impedance front-end amplifier, 197, 199 high-level data link control (HDLC), 18, 388 high performance parallel interface (HIPPI), 397 hold-off time, 583
homodyne receivers, 264 homogeneity, 58 hops, 444 maximum number of, 444 minimum average number of, 446 horizontal partitioning, 496 hot-potato routing See deflection routing hub topology, 442
architecture, 445 example, 444-445 illustrated, 442 number of wavelengths, 448
See also lightpath topologies hybrid fiber coax (HFC) networks,
592, 598 architecture, 598 enhanced, 598-599 illustrated, 596 ideal receiver, 252-253 imaging plane, 120 impedance, 743 concept, 745 input, 745 intrinsic, 743, 745 load, 745 incumbent LECs (ILECs), 3 induced electric polarization, 56 information model (IM), 499-500 attributes and functions, 499 classes of objects, 499 examples, 499-500 input buffering, 635, 639 input impedance, 745 insertion loss, 113,200-201 bulk mechanical switches, 209 uniformity, 200-201
integer linear program (ILP), 452 integrated services digital network (ISDN), 597 intensity-dependent refractive index, 85 interchannel crosstalk, 299, 301-303 power penalty, 301,303 sources, 301
See also crosstalk
Trang 10interchannel spacing, 344-345
interdomain routing protocol, 392
lnterexchange carriers (IXCs), 3
interference, 117
interference length, 473
interferometric techniques, 220-223
interleaving, 271-272
depth, 272
multistage, 149-151
intermodal dispersion, 35, 36, 308
geometrical optics approach and, 53
graded-index fibers and, 54
link length and, 308
reducing, 52
time spread due to, 52
See also dispersion
intermodulation products, 243
International Standards Organization (ISO), 16
International Telecommunications Union (ITU)
equal frequency spacing, 346
fiber standards, 721
grid, 30, 31,439
layers within optical layer, 504
management standards, 722-723
optical networking standards, 722
SDH standards, 721-722
standards, 721-723
wavelength grid, 347
wavelength standardization, 346
See also standards
Internet Protocol (IP), 7, 363,388-395
assured forwarding (AF) packets, 392
as common link layer, 674, 675
expedited forwarding (EF) packets, 392
explicitly routed paths, 393
forwarding, 390-392
label-switched router (LSR), 392-394
in layered hierarchy, 389
layering structures, 388
multiprotocol label switching (MPLS),
392-394
network failure, 559
over ATM over SONET, 20
over SONET, 19-20
over WDM, 388, 389
over WDM variants, 677-678
protection and, 558-559
QoS, 392
routing, 390-392
See also client layers; IP layer
Internet service providers (ISPs), 3 interoperability, 530
intersymbol interference (ISI), 49, 246 deliberate introduction of, 246 from PMD, 321
intrachannel crosstalk, 299-301
causes of, 299
FWM manifestation as, 331 level, 301
power penalty, 300, 301 source illustration, 300
See also crosstalk intradomain routing protocol, 391
intraoffice connections, 375
intrinsic impedance, 743,745 ionization coefficient ratio, 255
IP layer
as common link layer, 674, 675 maturity, 675
on top of optical layer, 676 QoS guarantees, 676
See also Internet Protocol (IP) isolators, 112-115, 227 insertion loss, 113 isolation, 113
parameters, 113 polarization-independent, 115 principle of operation, 113-115 uses, 112-113
isotropy, 57 Just-Enough-Time (JET)protocol, 649 KEOPS (Keys to Optical Packet Switching), 650-652
broadcast-and-select packet switch, 653 demonstrations, 650
predecessor, 650 switch controller, 651 wavelength-routing packet switch, 652 label distribution protocol with constrained routing (CR-LDP), 394
label-switched paths (LSPs), 392, 558-559
alternate, 559 failure, 394
packets, 393,558
label-switched router (LSR), 392-394, 524 label forwarding, 393
receiving packets, 392