This is the outbound counterpart, counting Mode Config payloads this device has sent to the peer over this tunnel, per its description - relevant when this device is the head-end assigning an address or attributes to a client. An admin monitoring a VPN concentrator expects OutConfigs to increment once per client connection as the internal IP is handed out; a client tunnel that's up but shows OutConfigs at 0 means the head-end never dispatched an address lease. That gap is a fast way to catch a broken address-pool configuration.