When per-prefix accounting is enabled, this counter tracks the total bytes, as opposed to packet count, switched to this specific destination prefix. Byte counts specifically let an admin estimate actual bandwidth consumption toward a given prefix, which packet counts alone cannot reveal since packet size varies enormously between, say, VoIP traffic and bulk file transfer toward the same destination. Comparing this counter's growth against cefPrefixPkts for the same prefix could reveal an average packet size of around 1200 bytes, suggesting bulk data transfer rather than small VoIP packets are dominating traffic to that destination.