对GGSN发起的更新的疑问

hycl5410

TS 29.060

An Update PDP Context Request may also be sent from a GGSN to a SGSN to re-negotiate the QoS of a PDP context. The GGSN-initiated Update PDP Context Request can also be used to provide a PDP address to the SGSN (and MS). The latter shall be used by GGSN when it acts as a DHCP Relay Agent or Mobil IP Foreign Agent.
...

只讲了这么点，后续流程没有讲。

TS 23.060

If the MS negotiates a PDP address with the PDN after PDP context activation in case of External PDN Address Allocation, it is the responsibility of the MS and the PDN to allocate and release the PDP address by means of protocols such as DHCP or MIP. In case of DHCP, the GGSN provides the function of a DHCP Relay Agent as defined in RFC 2131 [47] and RFC 1542 [45]. In case of MIP, the GGSN provides the function of a Foreign Agent as defined in RFC 3344 [46].

综合起来看，看起来像是这样的，GGSN通过update pdp告知SGSN，SGSN再通过modify pdp告知UE PDP地址变化。而这个PDP应该不会被去激活掉。

现网中应该几乎看不到这种场景...

hycl5410

sqm2050 发表于 2013-3-18 19:06
谢谢您的回复。
就是GGSN在更新报文中带着端用户地址，SGSN接收到了，再发个消息通知到手机，然后告诉GG ...

我从没在现网遇到过这种场景，于是也不知道具体的信令流程和用法是如何的。
可以肯定的是，wap类和net类的公众apn是不会存在这种场景的。但是SGSN和GGSN发起的update pdp很常见啊，比如qos变化，rat变化，inter sgsn rau等。如果不匹配TEID对的话，会有很多问题的哦。