This read-write parameter enables or disables frame sequence numbering on this PVC to detect lost or out-of-order frames across the Frame Relay service. Network engineers enable sequence detection when both ends of the PVC have TSUIQ devices (or compatible equipment) to ensure end-to-end frame integrity; it should remain disabled for PVCs terminating on other equipment that does not support this feature. For example, if sequence numbering is enabled and a frame arrives with a sequence number out of order, the device can alert the network engineer to potential carrier service issues or corruption.