This is the byte-volume counterpart to cienaCesAclRuleInstanceStatsPacketCount, again scoped to one specific attachment instance of the rule's parent profile rather than summed device-wide, letting an admin see exactly how much traffic weight a rule is generating on one particular interface/direction attachment. An admin combines this with the instance-level packet counter to compute per-attachment average packet size, useful for capacity planning on a specific link rather than a device-wide aggregate that could mask uneven load across several attachments. For example, an admin noticing device-wide byte counts for a rule are high might use this per-instance field to discover that nearly all of that traffic weight is actually concentrated on just one particular interface attachment, informing where to focus a bandwidth or policy review.