This read-only Counter64 counts the bytes this PM instance successfully forwarded out on egress. Admins trend this against the interface's provisioned bandwidth to see how close the service is running to its ceiling, since forwarded bytes — not accepted bytes — reflect what actually left the box; because it is drawn from this table's currently-accumulating, short-interval bin, it reflects only the last few minutes of activity, so it's the value to watch for a fast-forming problem rather than a long-term trend. On EVC 105 (E-Line, 100 Mbps CIR/1 Gbps EIR), this might read 175,000,000 bytes over the last 15 minutes — a number an admin would divide by the bin length to sanity-check it against the port's 1,000,000,000-bps ceiling.