This read-write value sets the requested cell/frame transfer delay for this circuit in microseconds, valid for PVCs in the range 1 to 0x00FFFFFF, with 0x00FFFFFF as the default meaning 'not valid' (i.e., no specific delay requirement requested). This is the QoS contract input side that pairs with the read-only cktAccumCTD measurement: the admin states a target here, and the switch reports actual achieved delay elsewhere, letting the two be compared for SLA compliance. An engineer provisioning a latency-sensitive PVC for interactive traffic might set cktReqCTD to 5000 microseconds, then later poll cktAccumCTD to confirm the network is actually meeting that requested bound.