MIB文件中的GROUP作用？

例如Q-BRIDGE-MIB 里的节点 qBridgeBaseGroup
+--qBridgeConformance(2)
|
+--qBridgeGroups(1)
| |
| +--**_qBridgeBaseGroup_**(1)
| +--qBridgeFdbUnicastGroup(2)
| +--qBridgeFdbMulticastGroup(3)
| +--qBridgeServiceRequirementsGroup(4)
| +--qBridgeFdbStaticGroup(5)
| +--qBridgeVlanGroup(6)
| +--qBridgeVlanStaticGroup(7)
| +--qBridgePortGroup(8)
| +--qBridgeVlanStatisticsGroup(9)
| +--qBridgeVlanStatisticsOverflowGroup(10)
| +--qBridgeVlanHCStatisticsGroup(11)
| +--qBridgeLearningConstraintsGroup(12)
| +--qBridgeLearningConstraintDefaultGroup(13)
| +--qBridgeClassificationDeviceGroup(14)
| +--qBridgeClassificationPortGroup(15)
| +--qBridgePortGroup2(16)

        在mib文件中是这样的

 qBridgeBaseGroup OBJECT-GROUP
    OBJECTS {
        dot1qVlanVersionNumber,
        dot1qMaxVlanId,
        dot1qMaxSupportedVlans,
        dot1qNumVlans,
        dot1qGvrpStatus
    }
    STATUS      current
    DESCRIPTION
        "A collection of objects providing device-level control
        and status information for the Virtual LAN bridge
        services."
    ::= { qBridgeGroups 1 }

不知道GROUP是做什么用的，是用来产生trap的嘛？
求教

应该是分组而已，就像一个树的节点，要获取信息需要group下的具体oid，或者可以group节点值snmpwalk一组snmp信息。