D-Link DSL 2740B - Manual (Page 38)

DSL-2740B Wireless ADSL Router User Guide
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ADSL Settings Window
Additional information for you to help you configure your WAN connections:
ATM Settings:
The ATM settings in the ADSL Settings windows for the different connection types can be used to adjust QoS
parameters for ADSL clients. This may not be available to all ADSL accounts.
ATM Parameters Description
PVC
The Router supports using up to eight multiple virtual connections. This
window allows the user to configure WAN settings for all the available
connections (see instructions below on how to set up Multiple Virtual
Connections). Use the PVC drop-down menu to select the connection (Pvc0
to Pvc7) you want to configure. Since most users will use only a single
connection, the default setting Pvc0 can be used for any changes made to
the WAN settings.
VPI
The Virtual Path Identifier is used with the VCI to define a dedicated circuit
on the ATM network portion of the connection to the Internet and WAN.
Most users will not need to change this setting.
VCI
The Virtual Channel Identifier is used with the VPI to define a dedicated
circuit on the ATM network portion of the connection to the Internet and
WAN. Most users will not need to change this setting.
Virtual Circuit
As with the PVC setting, this is mainly for use by clients who are configuring
the Router for multiple virtual connections. Use this to enable or disable the
PVC you are currently configuring. By default, the Pvc0 is Enabled and the
remaining PVCs are disabled.
Service Category
The ATM settings allow the user to adjust ATM Quality of Service (QoS) or
traffic parameters to suit specific traffic requirements. For applications or
circumstances where packet loss or packet delay is a concern, ATM QoS can
be adjusted to minimize problems. For most accounts, it will not be
necessary to change these settings. Altering QoS settings can adversely
affect performance of some commonly used Internet applications.
If you plan to change QoS or traffic parameters, contact your ISP or
network services provider for information on what types of adjustment are
available or possible for your account. Your ISP may not support the class
of service you want to use.
To adjust ATM QoS parameters, select one of the Service Categories listed
here and type in the PCR value in the entry field below. For the VBR service
category, an additional parameter (SCR) must also be defined.
UBR – Unspecified Bit Rate, this is the default category used for general-
purpose Internet traffic where normal levels of packet loss and delay are
acceptable. For some applications or for multiple connection accounts, it
may be desirable to specify the PCR.
CBR – Constant Bit Rate, usually used in circumstances where very low
packet loss and very low Cell Delay Variable (CDV) are desirable.
VBR – Variable Bit Rate, usually used when network traffic is characterized