This read-only PerfTotalCount reports the count of frames successfully transmitted on the DSL port, scoped to the DSL port's current, still-accumulating measurement period (not yet rolled into the interval history). Operationally, it's the baseline throughput indicator for outbound traffic and confirms the port is actually pushing data toward the customer. For example, an admin comparing successive live polls of this counter can estimate the port's current outbound throughput while a test is underway.