This read-create Integer32 (0..65535) is the Leaf Reference (EndPointReference) of the call on this interface, used to support tracing a specific leaf of a p2mp call; for a p2p call the NMS should set it to 0. An administrator sets this when tracing a point-to-multipoint connection to select which specific destination leaf the trace should follow. For example, tracing a p2mp video distribution call one leaf at a time, an engineer sets cwspConnTraceLeafRef to each leaf's reference in turn to trace every branch of the call.