DSL-2520U
ADSL2/2+ Router with USB and Ethernet Ports
User Manual
Configuring via Web-based Interface
Parameter
Description
QoS
A class of traffic for this connection.
UBR
(
Unspecified Bit Rate
): The UBR service is used for applications 
that allow various delays and losses of packets. It is appropriate to 
use the UBR service for text/data/image transfer applications, as 
well as messaging, distribution, retrieval, and remote terminal 
applications.
UBR With PCR
(
Unspecified Bit Rate with Peak Cell Rate
): The UBR service is 
used for applications that allow various delays and losses of 
packets. The Peak Cell Rate is a determining factor in how often 
cells are sent in an effort to minimize lag or jitter caused by traffic 
inconsistencies. When you select this value from the drop-down list, 
the 
Peak Cell Rate
field is displayed. Specify a required value (in 
cells per second).
CBR
(
Constant Bit Rate
): This service is used for applications that 
require a constant data rate. It is mostly used for transferring 
uncompressed audio and video, e.g. videoconferencing, interactive 
audio (telephony), audio/video distribution (television, distance 
education, e-shops), and retrieval (video-on demand, audio 
libraries). When you select this value from the drop-down list, the 
Peak Cell Rate
field is displayed. Specify a required value (in 
cells per second).
Non Realtime VBR
(
Non-Real-time Variable Bit Rate
): This service can be used for 
transferring data that have critical response-time requirements, e.g. 
air ticket booking, bank transactions, and process monitoring. When 
you select this value from the drop-down list, the 
Peak Cell Rate
, 
Sustainable Cell Rate
, and 
Maximum Burst Size
fields are 
displayed. Specify required values.
Realtime VBR
(
Real-time Variable Bit Rate
): This service is used for delay-
sensitive applications such as real time video. The Rt-VBR provides 
higher network flexibility than the CBR service. When you select 
this value from the drop-down list, the 
Peak Cell Rate
, 
Sustainable Cell Rate
, and 
Maximum Burst Size
fields are 
displayed. Specify required values.
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