This OID is a running total, in octets (bytes), of all outbound traffic transmitted on this 40 Gbps Ethernet (40GbE) interface since its statistics were last cleared. Comparing this outbound byte counter against the inbound one over the same interval lets an admin see whether traffic on this link is roughly symmetric or heavily skewed in one direction, which matters when planning capacity. For example, on a 40GbE trunk aggregating several client services, an outbound octet count that grows far faster than the inbound count would indicate the link is carrying mostly egress-bound traffic, such as a backup or replication push.