This attribute is a vector of two elements that specify the quality of
service parameters for the backward direction for this connection.
This attribute is used for SPVC connections.
The cdv element specifies the acceptable peak-to-peak Cell Delay
Variation (CDV) of real-time connections (CBR and rt-VBR). It is
signalled through the extended QoS information element.
The clr specifies the acceptable Cell Loss Ratio (CLR) of CBR, rt-
VBR, and nrt-VBR connections. It is signalled through the extended
QoS information element.