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 the most recently completed 24-hour bin, frozen once the day rolled over, it is frozen and safe to use for day-over-day comparison, since no further traffic will ever be added to it. On a 1 Gbps UNI feeding a business Ethernet Private Line, a live reading of 794,936,994 bytes/sec against a 1,000,000,000-bps port tells an admin roughly how close to full the link is running right now.