在进行网络设备测试之时,遇到问题,对关于GGSN重复发起Update PDP Context procedure的流程有些疑问,麻烦指点。
背景描述:
UE在正常attach并激活一个PDP context后,用户发起一个HTTP请求。在GGSN侧,GGSN根据该HTTP业务请求检测到该业务能匹配到某一个Qos,则GGSN往SGSN发起update PDP context request以修改该PDP context的Qos。SGSN在收到GGSN的请求后,会根据自己情况确定一个negotiated-Qos(比GGSN请求的Qos低),之后返回update PDP context response给GGSN完成修改Qos的过程。这样,UE的HTTP业务可正常进行。
相关协议描述:(29.060)
The QoS values supplied in the Update PDP Context Request may be negotiated downwards by the SGSN. The negotiated values or the original value from GGSN is inserted in the Quality of Service Profile information element. This information element shall be included if the Cause contains the value "Request accepted" and a QoS information element was supplied in the corresponding request message.