Chapter 17 xDSL Profiles Setup
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17.2 ATM QoS
ATM Quality of Service (QoS) mechanisms provide the best service on a per-flow guarantee.
ATM network infrastructure was designed to provide QoS. It uses fixed cell sizes and built-in
traffic management (see
). This allows you to fine-tune the levels of
services on the priority of the traffic flow.
17.3 Traffic Shaping
Traffic shaping is an agreement between the carrier and the subscriber to regulate the average
rate and fluctuations of data transmission over an ATM network. This agreement helps
eliminate congestion, which is important for transmission of real time data such as audio and
video connections.
"
Traffic shaping controls outgoing (downstream) traffic, not incoming
(upstream).
17.3.1 ATM Traffic Classes
These are the basic ATM traffic classes defined by the ATM Forum Traffic Management 4.0
Specification.
17.3.1.1 Constant Bit Rate (CBR)
Constant Bit Rate (CBR) is an ATM traffic class that provides fixed bandwidth. CBR traffic is
generally time-sensitive (doesn’t tolerate delay). CBR is used for connections that
continuously require a specific amount of bandwidth. Examples of connections that need CBR
would be high-resolution video and voice.
17.3.1.2 Variable Bit Rate (VBR)
The Variable Bit Rate (VBR) ATM traffic class is used with bursty connections. Connections
that use the Variable Bit Rate (VBR) traffic class can be grouped into real time (rt-VBR) or
non-real time (nrt-VBR) connections.
The rt-VBR (real-time Variable Bit Rate) type is used with bursty connections that require
closely controlled delay and delay variation. An example of an rt-VBR connection would be
video conferencing. Video conferencing requires real-time data transfers and the bandwidth
requirement varies in proportion to the video image’s changing dynamics.
The nrt-VBR (non real-time Variable Bit Rate) type is used with bursty connections that do
not require closely controlled delay and delay variation. An example of an nrt-VBR
connection would be non-time sensitive data file transfers.
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Страница 8: ...Safety Warnings IES 1248 71 73 User s Guide 8 ...
Страница 38: ...List of Tables IES 1248 71 73 User s Guide 38 ...
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Страница 51: ...Chapter 2 Hardware Installation IES 1248 71 73 User s Guide 51 Figure 6 IES 1248 Frame Ground Frame Ground ...
Страница 52: ...Chapter 2 Hardware Installation IES 1248 71 73 User s Guide 52 ...
Страница 60: ...Chapter 3 Front Panel Connections IES 1248 71 73 User s Guide 60 ...
Страница 68: ...Chapter 4 MDF Connections IES 1248 71 73 User s Guide 68 ...
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Страница 81: ...Chapter 7 Introducing the Web Configurator IES 1248 71 73 User s Guide 81 Figure 30 Logout ...
Страница 82: ...Chapter 7 Introducing the Web Configurator IES 1248 71 73 User s Guide 82 ...
Страница 110: ...Chapter 12 User Account IES 1248 71 73 User s Guide 110 ...
Страница 116: ...Chapter 13 Switch Setup IES 1248 71 73 User s Guide 116 ...
Страница 118: ...Chapter 14 IP Setup IES 1248 71 73 User s Guide 118 ...
Страница 150: ...Chapter 17 xDSL Profiles Setup IES 1248 71 73 User s Guide 150 ...
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Страница 166: ...Chapter 19 VLAN IES 1248 71 73 User s Guide 166 ...
Страница 184: ...Chapter 22 Multicast VLAN IES 1248 71 73 User s Guide 184 ...
Страница 216: ...Chapter 30 2684 Routed Mode IES 1248 71 73 User s Guide 216 ...
Страница 222: ...Chapter 31 PPPoA to PPPoE IES 1248 71 73 User s Guide 222 ...
Страница 226: ...Chapter 32 DSCP IES 1248 71 73 User s Guide 226 ...
Страница 240: ...Chapter 36 Syslog IES 1248 71 73 User s Guide 240 ...
Страница 248: ...Chapter 37 Access Control IES 1248 71 73 User s Guide 248 ...
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Страница 259: ...Chapter 39 Alarm IES 1248 71 73 User s Guide 259 ...
Страница 260: ...Chapter 39 Alarm IES 1248 71 73 User s Guide 260 ...
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Страница 296: ...Chapter 44 Commands IES 1248 71 73 User s Guide 296 ...
Страница 304: ...Chapter 45 Command Examples IES 1248 71 73 User s Guide 304 ...
Страница 320: ...Chapter 47 DHCP Commands IES 1248 71 73 User s Guide 320 ...
Страница 328: ...Chapter 48 IEEE 802 1Q Tagged VLAN Commands IES 1248 71 73 User s Guide 328 ...
Страница 334: ...Chapter 49 MAC Commands IES 1248 71 73 User s Guide 334 ...
Страница 348: ...Chapter 50 IGMP Commands IES 1248 71 73 User s Guide 348 ...
Страница 352: ...Chapter 51 Packet Filter Commands IES 1248 71 73 User s Guide 352 ...
Страница 362: ...Chapter 53 Firmware and Configuration File Maintenance IES 1248 71 73 User s Guide 362 ...
Страница 394: ...Chapter 55 ADSL Commands IES 1248 71 73 User s Guide 394 ...
Страница 418: ...Chapter 56 Virtual Channel Management IES 1248 71 73 User s Guide 418 ...
Страница 424: ...Chapter 57 ACL Commands IES 1248 71 73 User s Guide 424 ...
Страница 436: ...Chapter 58 Troubleshooting IES 1248 71 73 User s Guide 436 ...
Страница 437: ...437 PART VI Appendices and Index Product Specifications 439 Legal Information 449 Index 457 ...
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Страница 448: ...Appendix B Removing and Installing a Fuse IES 1248 71 73 User s Guide 448 ...
Страница 452: ...Appendix C Legal Information IES 1248 71 73 User s Guide 452 ...
Страница 464: ...Index IES 1248 71 73 User s Guide 464 ...