This attribute specifies the default reliability class of routing for all
calls (from the DTE to the network) using this particular Dna. The
chosen default reliability class of routing normally applies to all
packets (including the call packets) travelling into the network.
A value of high specifies that packets are to be overflowed or
retransmitted at various routing levels. Typically high reliability
results in duplication and disordering of packets in the network,
when errors are detected or during link congestion. The VC handles
the duplication and disordering to ensure that packets are delivered
to the interface in the proper sequence and without duplication.