This is applicable on Releases 5.1.4 and 5.2.0 of the VCO4K software.
When used in an NFAS Group, ICC-T1s must be configured with SPAN_TYPE = SF_NR or ESF_NR depending on whether the controlling ICC-PRI Spans are set to SF or ESF respectively.
This disables Robbed-Bit signaling
on the ICC-T1. Setting SPAN_TYPE to either SF or ESF causes a
significant reduction in the call load that a single ICC can handle.
This in turn reduces the total call load capacity of the switch