This read-only Counter64 reports the transmit byte rate for this PM instance, sampled per second. Admins compare this to the port's provisioned egress bandwidth in real time to see whether a service is currently saturating its allocation, well before a daily or 24-hour total would reveal it; because it is drawn from this instance's running statistics bin, it behaves like a long-running total rather than a rotating window, so admins baseline against it instead of expecting it to reset daily. On EVC 105 (E-Line, 100 Mbps CIR/1 Gbps EIR), a live reading of 593,874,333 bytes/sec against a 1,000,000,000-bps port tells an admin roughly how close to full the link is running right now.