This is the outbound counterpart to cktInFrames, letting the admin see how many frames this circuit is delivering toward the customer, useful for spotting an imbalance where inbound traffic is high but outbound delivery is lagging. For example, a circuit with steadily climbing cktInFrames but flat cktOutFrames on the same PVC would point to frames being accepted into the network but not reaching this delivery leg, consistent with congestion or a routing fault further along the path.