See BSSIDs; SSIDs Service Switching Point SSP, 42 service-level agreements SLAs, 97–98 Session Description Protocol.. See SDP format Session Initiation Protocol... See standards Spectr
Trang 1SDP (Session Description Protocol) format, 21
codec negotiations and, 53–55 description, 53, 53t
responding description, 54–55, 55t
as a text-based protocol, 53 sectorization, 120
secure password-based authentication, 336
secure RTP, 52, 55, 341–342 secure SIP, 32
Secure Socket Layer, TLS replacing, 334
secure wireless network, 169–170 security
for 802.11, 169–192
in controller-based architecture, 121
principles of, 324 technologies in Wi-Fi, 170–180 for voice mobility networks, 323 security handoff overhead, reducing, 252–253
segment, in Ethernet, 78 self noise, 135–136 send loudness, 61–62 sender’s noise, 61–62 sequence control field, 111, 111t Sequence field, in TCP, 88 sequence number
in IPsec, 338–339
in the sequence control field, 114 serial number, of a certificate, 333 serial protocol, Ethernet as, 77–78 server failure codes, in SIP, 30 Server Hello Done message, 187–188, 188t
Server Hello message, 187–188, 188t Service Control Point (SCP), 42 service disruption, during 802.11r transitions, 276–277 service period, in WMM Power Save, 213
“service provider,” for Wi-Fi, 233
service set identifier See BSSIDs;
SSIDs Service Switching Point (SSP), 42 service-level agreements (SLAs), 97–98
Session Description Protocol See SDP
format
Session Initiation Protocol See entries
at SIP session lifetime, 183 Session-Expires header, 21 SETUP message, in Q.931, 41 720p high-definition video, 350–351 1700MHz band, 302
Shannon’s Law, 137–138 shared medium, 113–115 short guard interval, in 802.11n, 163–164
short preambles, 157 short slots, for 802.11ag, 161 sidetone, lack of, 62 signal(s)
as complex numbers, 195 modulating, 195 phase and attenuation of, 196–197 signal filters, airways as, 49–50 signal power level, 134 signal propagation properties, 135–136
signal strength See also power
sudden drop causes, 244 throughout a one-room office, 133, 134f
Signal Transfer Points (STPs), 42 signaling channel, 5, 7–9 signaling protocols, 11–42 Signaling System #7 (SS7), 42, 42
signal-to-noise ratio See SNR
signature algorithm, in a certificate, 333 signing authority, 330
silence suppression, 54–55 SIM (Subscriber Identity Module) card, 298
SIM authentication, 337 simultaneous impairment, 62 simultaneous ring PBX feature, 10–11 sine wave
basic carrier as, 193–194 representing complex function, 195
SIP (Session Initiation Protocol) ACK request from caller to proxy, 25t
architecture, 12–15, 14f authentication challenge, 31t authentication response, 31t based on HTTP, 12 busy everywhere rejection, 27t busy here rejection, 26, 27t calls-based, 14
compared to H.323, 32 described, 12–32 global failure codes, 30 goal of, 12
hanging up, 27 in-progress codes, 28 invitations in, 15 media gateways, 15 messages in text, 12 not voice specific, 14
OK response from proxy to caller,
23, 25t over TCP, 341 phone conference management and, 14
placing a call, 19–25 for point-to-point video calls, 361 proxy, 13, 15
redirection codes, 28 REGISTER request, 16t
registrar, 13 registration in, 15–19 rejected calls, 26–27 request failure codes, 28–29 response codes, 27–30 ringing response from, 23, 23t server failure codes, 30 between specific infrastructure resources, 28–29 success code, 28 SIP authentication, 30–31 SIP headers (HTTP), 16–17
“sip:” marker, for a URI, 13 SIP-based admission control, 214–215 SIP-based schemes, 230
SIPS (SIP with TLS), 32, 341– 342 site survey
after an adaptive power control run, 281–282
tools, 286, 288 with voice in mind, 286 64-QAM, 159
64-QAM constellation, 159, 160f 16-QAM, 159
16-QAM constellation, 159, 160f
Skinny Client Control Protocol See
SCCP Skype described, 35–38 freeing from PSTN integration, 37–38
high-bitrate codecs, 37–38 not manageable in an enterprise sense, 35–37
SLAs (service-level agreements), 97–98
slash notation, 81, 85–86 slots
in 802.11ag, 161
in Ethernet, 78–79 for a radio, 146 Slotted ALOHA, 146 slow start process, in TCP, 89–90 SNAP (Subnetwork Access Protocol) header, 111, 112t
SNR (signal-to-noise ratio) minimum, 136–137 per-stream, 202 relation to data rate, 137– 138
in the R-value, 60–62 sockets, 86–87, 362 soft handoffs, 273, 301 softphones, 12 soft-state table, 79–80 Source, in IPv6, 86, 86t source address (SA), 113 source bits, in 802.11ag, 161 Source field, in IPv4, 82 Source Port
in TCP, 88
in UDP, 87
Trang 2sources
Ethernet addresses seen as, 79–80
of noise in Wi-Fi networks, 134
space-time block codes (STBC), 164
spatial streams
capacity of, 202
in MIMO, 163–164
speaker, in a phone, 5–8
specifications See standards
SpectraLink company, 38
SpectraLink Voice Priority See SVP
spectrum analyzers, 287
spectrum management, 228–229
SPI (Security Parameters Index),
338–339
spreading, in 802.11, 153–154
SRTP (secure RTP), 52, 55, 341–342
SS7 (Signaling System #7), 42, 42
SSIDs (service set identifiers), 107 See
also BSSIDs
in a beacon request, 264–265
best practices, 107–108
broadcast suppression, 107–108
hiding, 107–108
naming the network, 107–108
typing, 108
SSL (Secure Socket Layer), TLS
replacing, 334
SSLv3 peers, 335
SSP (Service Switching Point), in SS7,
42
SSRC (Synchronization Source), 51
stacks, in phones, 5–7
standalone access points, 120, 258–259,
260f
standalone wireline, 120
standards, 3–4
standby mode, 209
stateful classification, of packets, 95
stateless manner, 95
static architectures, 123
static microcell over-the-air
architectures, 123
statistics, on expected quality of calls,
230
status code, in Association Response,
117
STBC (space-time block codes), 164
sticky client problem, 242–244, 243f
still images See also pictures
compression, 352–357
STPs (Signal Transfer Points), 42
stream cipher, 171–172
streaming packets, 54–55
strict prioritization scheduler, 96
strict time sharing, 299
subcarriers, in OFDM, 158
subnet, distributing, 120
subnet mask, 83
Subnetwork Access Protocol (SNAP),
111, 112t
subpixels, 352 subscriber, Q.931 point of view, 41 success code, in SIP, 28
supplicant
in 802.1X, 252–253
in EAP, 329 software, 180 Surplus Bandwidth Allowance, 216–218
SVP (SpectraLink Voice Priority) architecture of, 38, 39f described, 38–40 designed for Wi-Fi, 40 gateway, 38
symbols
in 802.11, 153–154 errors involving, 155, 157f
in the modulation function, 195–196
SYN flag, in TCP, 88, 88t Synchronization Source (SSRC), 51
T
T-Mobile, UMA for voice mobility networks, 321
T1 line, 40 talker echo, 62–63 TCP (Transmission Control Protocol) applications, 362
communicating using SIP endpoints, 32 described, 87–90 flags field, 88, 88t flow control techniques, 89–90
as handshaking protocol, 89–90 inappropriate for voice mobility, 90
packet format, 88t prioritizing traffic, 362 refusing to allow any loss, 90 SCCP running on, 34 stream, 89
tracking flow state, 89 traffic, 138b for video, 90 TCP Report element, 268, 268t TCP-based streaming, for video, 361 TDMA (time division multiple access), 299
technology stacks, in phones, 5–7 telephone communications, voice for, 43
telephone switch, 7, 79
telephones See entries at phone
telephony application, 5–7
Temporal Key Integrity Protocol See
TKIP 10BASE-T, 78 terminals, in H.323, 32–33 text messages, in SIP, 12 text “phone numbers,” in SIP, 13
Thawte Consulting certificate authority, 333
theft, preventing for handsets, 344–346 theft detection, 345
thermal noise, 134 thickness, of a network, 229
“Thin” wireline See controller-based
wireline
300 Mbps data rates, in 802.11n, 163 3G technologies, 301–303
three-dimensional visualization, 288 throughput
data rates and, 138b required by video, 350 TIDS (Traffic Identifiers), in WMM, 216
TIM (Traffic Indication Map), 209 time delay, of signals, 196–197 time division multiple access (TDMA), 299
time-based policies PBX feature, 10–11 timeslicing function, in SVP, 38–40 timing
in 802.11ag, 161
of scanning, 238 tinting, 353–354 TKIP (Temporal Key Integrity Protocol)
bridge from WEP to WPA2, 178 defined in WPA, 174
introduction of, 173–174 mode in WPA, 174
on WEP hardware, 176–177 TKIP sequence counter (TSC), 177 TLS (Transport Layer Security) described, 334–335
as outer tunnel in PEAP, 187 protecting SIP over TCP, 341 record types, 335t
TLS client Hello, 141, 187t T-Mobile, UMA for voice mobility networks, 321
To DS flags, 113
To field, in SIP, 18, 21
To line, in SIP, 17 Token Bucket Rate, in RSVP, 91 Token Bucket Size, in RSVP, 91 token buckets
metering flow of traffic, 97 used for policing, 98 working to regulate a flow, 91 toll-quality, MOS scale for, 58 TOS field, in IPv4, 92–93, 92t TOS precedence, 205 TOS/DSCP field, in IPv4, 82, 92 Total Length field, in IPv4, 82 TPC (transmit power control),
225–226 See also power control
Traffic Class field, in IPv6, 86, 92 traffic director, in Ethernet, 79–80 traffic ID, 268–269, 268t
Trang 3Traffic Identifiers (TIDS), 216 Traffic Indication Map (TIM), 209 traffic shaping, 95
described, 97–98 highlighting packet-based networks, 97–98 through some form of token bucket, 97
traffic specification See TSPEC
traffic streams
in WMM, 216
in WMM Admission Control, 216 transient interference, 229
transitions, in 802.11r, 255–257
Transmission Control Protocol See
TCP transmission retries, clients monitoring, 239–240
transmit beamforming, 164, 166–167 Transmit Opportunity (TXOP) Limit, 207
transmit power control (TPC),
225–226 See also power control
transmit stream metrics, 268–269 transmit stream request, 268–269, 268t
transmitted frame count, 269, 270t transmitter address (TA), 113
Transport Layer Security See TLS
transport mode
in IPsec, 338 payload in, 339 triggered reporting element, 268–269, 268t
trigger-enabled access categories, 212 triggers, for autonomous reports, 263
TS Info field, in a TSPEC, 216–218 TSC (TKIP sequence counter), 177 TSPEC (traffic specification), 91, 215 contents of, 216–218, 217t, 222f TTL (Time To Live) field, in IPv4, 82 TTLS (tunneled TLS), 336
tunnel mode, 338–339
2.5G See GPRS 2.75G technology See EDGE
technology 2100MHz band, 302
2 Mbps data rate, 155 2G technologies, 297–301 two-dimensional visualization, 288 TXOP limit (Transmit Opportunity Limit), 207
Type field
in EAP, 329–330
in WiMAX, 304 Type of Service (TOS), 92
U
UDP (User Datagram Protocol) described, 12, 86–87
as a lossy protocol, 23
packet format, 87, 87t RADIUS running on, 325 SIP running over, 12 UMA (Unlicensed Mobile Access), 320 UMA Network Controller (UNC), 320 UMTS (Universal Mobile
Telecommunications System), 301 new type of radio, 301–302 pursued by U.S GSM vendors, 303
requiring new spectrum, 302 way for even higher throughput, 302
underrun, of a voice recorder, 69 unequal load, same call producing, 221–222
Uniform Resource Identifier (URI), 12–13
United States, spectrum allocation, 103f Universal Mobile Telecommunications
System See UMTS
Universal Subscriber Identity Module (USIM), 302
Unlicensed Mobile Access See entries
at UMA Unlicensed National Information Infrastructure (U-NII), 104 unlicensed spectrum
benefits of the freedom from using, 104
other uses besides Wi-Fi, 130 upstream loss, monitoring, 230 upstream part, at the access point, 245 upstream transmissions, 118 upstream-only traffic stream, 216 URG flag, in TCP, 88, 88t urgent field, in TCP, 88 URI (Uniform Resource Identifier), in SIP, 12–13, 17
user agents, in SIP, 12–13, 18 user authentication, in ISAKMP, 341
User Datagram Protocol See UDP
user/password login, Access-Request for, 326, 328t
USIM (Universal Subscriber Identity Module), 302
utterances, in PESQ, 59
V
variance, of an antenna’s signal, 200 vendors
architectures possible with, 119, 119t
EV-DO (Evolution-Data Optimized) technology, 303 interoperability, 298
mobility domains across, 259 point of view of, 241 pursuing UMTS, 303 Version field, in TLS, 335 Version/Flow field, in IPv6, 86, 86t
Version/Header Length Field, in IPv4,
82, 82t vertical handoffs, between channels, 276
Via field, in SIP, 18 Via header, in SIP, 16–17 video
compression, 352–360 differences from voice, 350 discrete Fourier transform and, 357
encoding concepts, 350–352 networking, 362–363 sensitivity to loss, 350 video bearer, 360–361
video codecs, 360 See also codec(s)
video conferencing attractiveness of, 349 codecs for, 360 H.323 and, 32 requirements for effective, 361 video mobility, 349–364
video signaling, 361 video streams, 362 video transport
as the bearer, 360 real-time, 360–361 virtual carrier sense, 115, 143–144 virtual reality, as visualization tool, 288
virtual time, units of, 96–97 virtualization
of the BSS, 275 per-device containment provided
by, 125 segmenting client population, 275 architecture, 125
Wi-Fi partitions, 125 Virtual Cell,
visited gateway, 294 visitor location register (VLR), 292–293
visualization techniques, 288 voice
differences from video, 350 frequency of, 43
monitoring tools in wireless networks, 230 recording mechanisms, 43f
as sound waves, 43 sources for problems with, 231 unique nature of, 203–204 WMM providing priority for, 207–208
voice call(s) anatomy of, 5–11 behavior over Wi-Fi, 241 flows of information, 7 limiting in a cell, 208 moving parts of, 5, 6f placing, 5, 106
Trang 4voice certifications, 279–280
voice clients, as more proactive, 240
voice codecs See codec(s)
Voice Enterprise certification, 280
Voice Enterprise test, of the Wi-Fi
Alliance, 279–280
voice immobility, 1
voice lines, terminating, 346
voice mobility
concerns for, 289
described, 1–2
introduction to, 1–4
over Wi-Fi, 203–288
RF modifications for, 280–286
technologies addressing with
Wi-Fi, 214–230
technology behind, 5–55
Wi-Fi Alliance certifications for,
277–280
WiMAX problem, 305
voice mobility deployments
in the 2.4GHz band, 284
challenges to, 148
voice mobility devices
categories using Wi-Fi, 105–
106
documentation influencing handoff
behavior, 241–242
voice mobility handset See handset
voice mobility networks
as a company secret, 2–3
four- or five-digit dialing within, 9
interpreting the factors, 70
with less voice than data traffic,
281
with mostly voice traffic, 284
physical security for, 346–347
pipe in, 342
security for, 323
voice mobility site survey, 286
voice networks
IP-based, 73–90
keeping separate from data
networks, 346–347
voice over cellular networks, 299
voice over IP
networks, 59
pioneers, 75–76
voice packet arrival interval, 238
voice packets, client scanning between,
238
Voice Personal certification, 280
Voice Personal test, of the Wi-Fi
Alliance, 279
voice quality
determining, 58
elements of, 57–72
examining, 57–64
impact of inconsistent and variable
coverage on, 281
measuring, 70–72
monitoring for devices on the network, 229–230 monitoring for good, 287 non-IP effects on, 70 properties influencing, 64–70 voice traffic
distinctive over Wi-Fi, 347 high density, 284
at lower ratio to data, 281 prioritization for, 204 shorter in bytes than data traffic, 281
voice-aware radio resource management (RRM), 227–228 voicemail PBX feature, 10–11 voicemail service, 292 VPN, accessing enterprise network on the road, 343–344
VPN clients, in phones, 343–344
W
W-CDMA (Wideband-CDMA), 301–302
waveguide, environment serving as, 132–133
W-CDMA (Wideband-CDMA), 301–302
web security, certificates in, 332–333 webcasting, attractiveness of, 349 weighted random early detection (WRED), 99
WEP (Wired Equivalent Privacy), 116–117
author’s recommendation on, 170 described, 170–173
frame body, 173t keys in, 170–171 WFQ (weighted fair queueing), 96–97 white, as not a pure color, 351
“whys,” of Wi-Fi, 193–202 Wideband-CDMA (W-CDMA), 301–302
Wi-Fi advantages of, 101–106 approach to wireless, 137–148 basics of, 106–127
break-before-make handoff, 249–252
channels, 123 chip, 343 devices for, 105–106 differences from IEEE 802.11 standard, 102b
elements of, 127 engine, 242–244 enormity of, 2 handoff(s), 320 handoff protocol, 249–250 locations of, 105 maturity of, 105 mobility networks, 118
modes of power saving, 209–213 multicast, 363
multicast for, 363 noise generated by, 135 power connection into hands of clients, 232–233
radio types, 148–169 radios in SVP phones, 38–40 role in delivery of video, 362 security, 343
security technologies, 170–180 stretches (“bands”) of the radio spectrum, 104
SVP designed for, 40 voice mobility over, 203– 288
“whys” of, 193–202 Wi-Fi Alliance certification programs, 102b certifications for voice mobility, 277–280
certifications for voice within, 279 ensuring devices interoperate, 163 rule of thumb for voice certification efforts, 66 testing WMM devices, 278 trademark of, 102b Wi-Fi Alliance certificate example, 277, 278f sections of, 277 Wi-Fi Multimedia (WMM), 204 Wi-Fi networks
allowing the administrator to monitor voice, 287 associating with, 185 evaluating for suitability for voice, 318–319
handing off to, 319–320 handoff outside, 319 licenses not needed to operate, 102
as local to the campus, 306 mobility appliance management role, 309
Wi-Fi Protected Access See WPA
Wi-Fi Protected Access version 2
(WPA2) See WPA2
Wi-Fi to Wi-Fi handoffs, 319
Wi-Fi-clients See client(s)
Wi-Fi-only devices, 105–106 Wi-Fi-only handsets, 344 WiMAX
accessing channels, 303 base stations transmitting beacons, 304
basics of, 303–304 described, 303–305 frame format, 303, 304t
as a laptop option, 305 market acceptance and coverage areas, 305
running the licensed spectrum, 303 uses of, 305
Trang 5Window field, in TCP, 88 wire mesh, causing attenuation, 131
Wired Equivalent Privacy See WEP
wired networks, quality of service on, 90–99
wireless demand for, 104 Wi-Fis approach to, 137–148 wireless architectures, 802.11r in, 258–259
wireless controller, 121 wireless devices, 106 wireless loss, 64 wireless network management reporting tools, 287
wireless network virtualization, 125 wireless networks, in an enterprise private network, 69
wireless noise, non-802.11, 287 wireless radios, in phones, 5–7 wireless tool, 220
wireline, 120 wireline architecture, 119 wireline categorizations controller-based, 121–122 controllerless, 122 directly connected, 122– 123 standalone, 120
for wireless networks, 119 wireline networking technologies, 76
wireline networks handling large amount of traffic, 94
placing into the voice network, 342–343
quality of service, 91–92 wireline portion, of the voice mobility network, 346
wireline technologies, 106 within-band load balancing, 223 WLAN virtualization, 125 WMM (Wi-Fi Multimedia) certification, 278–279 changing backoff procedure, 206
described, 204, 207–208 header, 205
listing on certificates for voice devices, 277–278 Parameter Set information element, 207 parameters, 207t, 285 Power Save, 205–206, 212–213, 278
providing priority for voice, 207–208
quality of service with, 203–208 setting parameters away from defaults, 208
TOS precedence values in, 92–93
WMM Admission Control access points, 285 certification tests, 279 defaults causing problems with, 205–206
described, 215–219 details of concepts, 216 requirements of, 251 setting to mandatory or optional, 215
working for all traffic types, 218–219
WPA (Wi-Fi Protected Access) frame body, 177t version one in 802.11i, 173–174 WPA2, 174
AES and, 178–179 Enterprise security, 347 frame body, 179, 179t key hierarchy, 254 Wi-Fi certification requiring, 343 WRED (weighted random early detection), 99
WWW-Authenticate header, 31
X
X.509 format, 332–333
Y
YCbCr, 353