Pre-Congestion Notification described in [I-D.eardley-pcn-architecture] and earlier in [I-D.briscoe-tsvwg-cl-architecture] approach proposes the use of an Admission Control mechanism to limit the amount of real-time PCN traffic to a configured level during the normal operating conditions, and the use of a Flow Termination mechanism to tear-down some of the flows to bring the PCN traffic level down to a desirable amount during unexpected events such as network failures, with the goal of maintaining the QoS assurances to the remaining flows. In [I-D.eardley-pcn-architecture], Admission and Flow Termination use two different markings and two different metering mechanisms in the internal nodes of the PCN region. This draft proposes a mechanism using a single marking and metering for both Admission and Flow Termination, and presents an analysis of the tradeoffs. A side- effect of this proposal is that a different marking and metering Admission mechanism than that proposed in [I-D.eardley-pcn-architecture] may be also feasible, and may result in a number of benefits. In addition, this draft proposes a migration path for incremental deployment of this approach as an intermediate step to the dual-marking approach.