The source DESCRIPTION for this object is empty, so this is inferred from its name and Counter64 syntax: it tracks the total number of bytes sent out over this specific pseudowire to the identified peer. Admins use it to measure outbound bandwidth usage toward that particular remote peer, useful when one L2VPN fans out to several destinations with different link capacities. As an illustrative example, an admin notices this counter climbing much faster toward one peer than another, prompting a check of that peer's access-link capacity.