This read-only PerfTotalCount reports the count of frames successfully transmitted on the DSL port, scoped to one specific 15-minute bucket out of the 96 stored for that DSL port. Operationally, it's the baseline throughput indicator for outbound traffic and confirms the port is actually pushing data toward the customer. For example, a sudden drop in transmitted-frame counts in one 15-minute bucket, compared to neighboring buckets, can indicate a brief outage that a daily total alone would hide.