This INTEGER attaches a CIR/EIR metering policy to this PBB-TE transit's ingress traffic; per the description, a value of 0 means no ingress meter profile is attached. This explicit meaning tells an admin that transit traffic without an assigned meter ID simply flows unpoliced at this stage, relying on metering applied elsewhere, for example at the originating sub-port. Leaving this at 0 on a core transit segment that trusts metering already applied at the network edge, rather than double-metering traffic in the backbone, is a common configuration.