In this scheme, the whole work is divided into several modules. SNMP, carrying message between Policy Decision Point (PDP) and Policy Enforcement Point (PEP), acts as a signaling protocol.

• 方案中把具体实现分为几个模块来完成，并使用简单网络管理协议(SNMP)作为策略决策点和策略执行点之间消息传送的信令协议。