说明：  互联网短信网关（ISMG）是外部信息资源站实体（SP）与移动网内短信中心之间的中介实体，互联网短信网关一方面负责接收SP发送给移动用户的信息和提交给短信中心。另一方面，移动用户点播SP业务的信息将由短信中心通过互联网短信网关发给SP。另外，为了减轻短信中心的信令负荷，互联网短信网关还应根据路由原则将SP提交的信息转发到相应的互联网短信网关。互联网短信网关通过向汇接网关（GNS）查询的方式获得网关间的转发路由信息。
(Internet SMS gateway (ISMG) is an intermediary between entities in the external information resources station entity (SP) and the mobile network SMS center, Internet SMS gateway on the one hand is responsible for receiving the SP send mobile users the information and submitted to the SMS center. On the other hand, mobile users demand SP business information by SMS center distributed through the Internet SMS gateway SP. In addition, in order to reduce the signaling load of the SMS center, Internet SMS gateway should be based on the routing principles of the information submitted by the SP forwarded to the appropriate Internet SMS gateway. Internet SMS gateway gateway forwarding routing information obtained through queries to the tandem gateway (GNS).)