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IES-1248-51 User’s Guide
130
Chapter 17 xDSL Profiles Setup
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.
Note:
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.
Содержание IES-1248-51
Страница 1: ...IES 1248 51 ADSL2 IP DSLAM User s Guide Version 3 51 ABQ 1 3 2006 ...
Страница 4: ...IES 1248 51 User s Guide 4 Interference Statements and Warnings ...
Страница 22: ...IES 1248 51 User s Guide 22 Table of Contents Index 379 ...
Страница 30: ...IES 1248 51 User s Guide 30 List of Figures ...
Страница 34: ...IES 1248 51 User s Guide 34 List of Tables ...
Страница 47: ...IES 1248 51 User s Guide Chapter 2 Hardware Installation 47 Figure 6 IES 1248 51 Frame Ground Frame Ground ...
Страница 48: ...IES 1248 51 User s Guide 48 Chapter 2 Hardware Installation ...
Страница 62: ...IES 1248 51 User s Guide 62 Chapter 4 MDF Connections ...
Страница 73: ...IES 1248 51 User s Guide Chapter 7 Introducing the Web Configurator 73 Figure 29 Logout ...
Страница 74: ...IES 1248 51 User s Guide 74 Chapter 7 Introducing the Web Configurator ...
Страница 88: ...IES 1248 51 User s Guide 88 Chapter 9 Home and Port Statistics Screens ...
Страница 90: ...IES 1248 51 User s Guide 90 Chapter 10 System Information Figure 44 System Info ...
Страница 98: ...IES 1248 51 User s Guide 98 Chapter 12 User Account ...
Страница 104: ...IES 1248 51 User s Guide 104 Chapter 13 Switch Setup ...
Страница 106: ...IES 1248 51 User s Guide 106 Chapter 14 IP Setup ...
Страница 126: ...IES 1248 51 User s Guide 126 Chapter 16 xDSL Port Setup ...
Страница 140: ...IES 1248 51 User s Guide 140 Chapter 17 xDSL Profiles Setup ...
Страница 154: ...IES 1248 51 User s Guide 154 Chapter 19 VLAN ...
Страница 188: ...IES 1248 51 User s Guide 188 Chapter 28 2684 Routed Mode ...
Страница 192: ...IES 1248 51 User s Guide 192 Chapter 30 Syslog ...
Страница 210: ...IES 1248 51 User s Guide 210 Chapter 33 Alarm ...
Страница 240: ...IES 1248 51 User s Guide 240 Chapter 38 Commands ...
Страница 256: ...IES 1248 51 User s Guide 256 Chapter 40 Alarm Commands ...
Страница 262: ...IES 1248 51 User s Guide 262 Chapter 41 DHCP Relay Commands ...
Страница 282: ...IES 1248 51 User s Guide 282 Chapter 44 IGMP Commands ...
Страница 286: ...IES 1248 51 User s Guide 286 Chapter 45 Packet Filter Commands ...
Страница 292: ...IES 1248 51 User s Guide 292 Chapter 46 IP Commands ...
Страница 302: ...IES 1248 51 User s Guide 302 Chapter 48 SNMP ...
Страница 338: ...IES 1248 51 User s Guide 338 Chapter 49 ADSL Commands ...
Страница 358: ...IES 1248 51 User s Guide 358 Chapter 50 Virtual Channel Management ...
Страница 370: ...IES 1248 51 User s Guide 370 Chapter 51 Troubleshooting ...
Страница 378: ...IES 1248 51 User s Guide 378 ...