This read-create pointer is the transmit-direction counterpart of casfVcEndptRxTrafficDescrRow, identifying the traffic descriptor row for cells this endpoint sends outbound. A mismatch between this pointer's requested descriptor and casfVcEndptTxNegTrafficDescrRow's negotiated one reveals asymmetric negotiation, which happens when the far end's switch can support less bandwidth in one direction than the other. A connection could get its full requested transmit PIR while its receive PIR gets negotiated down, if the bottleneck exists only on the return path.