Buffalo Technology WBMR-G54 Manuel D’Utilisation

WBMR-G54 Wireless ADSL Router User Guide 

The ATM settings in the WAN 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.  

 

Additional ATM settings for PPPoE or PPPoA connections: 

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 

by bursts of packets at variable intervals, and some moderate packet loss 

and delay is acceptable. This category is typically used for audio and video 

applications such as teleconferencing. The network must support QoS Class 
2 to use VBR. 

Peak Cell Rate – The PCR is inversely related to the time interval between 
ATM cells. It is specified for all three service categories (UBR, CBR and 

VBR) in Kbps. 

 

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