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 the lifetime bin, which keeps accumulating until an operator explicitly clears it, a sudden plateau on an otherwise busy instance is itself a signal — most likely that someone cleared the stats rather than that traffic actually stopped. On EVC 212 (E-LAN) on a metro access ring, this might read 375,000,000 bytes over the 156 days since the counters were last cleared — a number an admin would divide by the bin length to sanity-check it against the port's 1,000,000,000-bps ceiling.