The GR-303 Interface Group Table. Minimum granularity for GR-303 provisioning is the Interface Group (IG) abstraction aka Internal Group. The Interface Group Table describes attributes for each provisioned GR-303 Interface Group and is also the base table for the augmenting Interface Group Control Channel Table. Each IG is configured manually by an administrator. Each IG entry (row) is indexed by a unique IG name. Where both active and standby Interface Groups exist, the same IG name refers to both the active and standby Interface Group. For all IG entries, the (shelf, slot) is unique. The IG name is an externally visible global name that refers to both the active and standby IGs. IG names are used for call routing and does not change during the IG lifetime. The maximum number of entries or Interface Groups is 'system-wide' and not bounded by a slot or card, but can span multiple cards and shelves. Each Interface Group is associated with the following tables: * augmenting Interface Group Control Channel row * DS1 Line Mapping Table * Line Circuit CRV Table * augmenting IG Statistics Current row * IG Statistics Interval Table * augmenting IG Statistics Total row After creating an IG entry an associated primary DS1 must be created. Without the primary DS1 an SNMP-SET operation is not allowed on any 303 tables except the deletion of the IG entry.