tmnxOamBuildPktPbbCtlEntry contains the definition of one PBB header used by the OAM Egress Finder. Fields that influence the routing by SROS of a packet containing a PBB header (e.g. Backbone Service Instance Identifier (I-SID)) are present. The other PBB header fields (e.g. Priority Code Point (I-PCP)) are absent. A row is created by SROS when: 1. tmnxOamBuildPktHdrType is set to 'pbb', OR 2. A tmnxOamBuildPktHdrOvrCtlTable table row is created with a tmnxOamBuildPktHeaderNum index which refers to a header with type 'pbb'. A row is destroyed by SROS when: 1. A tmnxOamBuildPktHdrCtlTable row with tmnxOamBuildPktHdrType = 'pbb' is destroyed, OR 2. A tmnxOamBuildPktHdrOvrCtlTable row which refers to a header with type 'pbb' is destroyed. A row created using creation clause 1, above, has the index object tmnxOamBuildPktNumOrZero=0. The zero indicates the PBB header is a base definition (not an override). A row created using creation clause 2, above, has tmnxOamBuildPktNumOrZero set to the tmnxOamBuildPktNum index of the parent tmnxOamBuildPktHdrOvrCtlTable row. The following example values for this table show the definition of a base I-SID field for header 1, and two overrides. Pkt Num Or Zero Header Num I-SID 0 1 16777213 10 1 16777214 255 1 16777215