Working mode indicates whether the selected switch can configure the RDT using common management information service (CMIS) over the Embedded Operations Channel (EOC) channel. There are two working mode states, active and passive. In the active mode, the seleted switch can configure the RDT for Call Reference Values (CRVs) over the EOC channel. In the passive state, CRVs can only be configured locally. Even with the switch in the active state, however, RDT is required to configure CRVs. This field can only be modified after setting the igAdminStatus of the IG record to outOfService. This field is mandatory when provisioning an interfaceGroupEntry.