协议上是如是说的“The SGSN shall include the IMSI in the PDU. As an exception, the SGSN may omit the IMSI in the PDU if the mobile station identified by the TLLI is in MM non-DRX mode period (i.e. during a GMM procedure for GPRS attach or routing area updating defined in 3GPP TS 24.008) and the SGSN does not have a valid IMSI.”也就是只有the mobile station identified by the TLLI is in MM non-DRX mode period 并且 the SGSN does not have a valid IMSI的情况下,DL_UNIDATA才不包含IMSI。那么什么时候才是这种情况呢? 我在从附着和PDP激活流程看Local和Foreigh TLLI的变化 (http://www.gprshome.com/forum.php?mod=viewthread&tid=603&page=3#pid14719)所附的包里只看到在Gmm information 的情况下DL_UNIDATA才不包含IMSI,其他的DL_UNIDATA都包含IMSI,而且我从其他地方找的包也是这样。 是不是出了Gmm information ,其他的gprs附着,去附着,激活,去激活,路由区更新等的下行DL_UNIDATA都会包含IMSI呢? 如果不是,那还有那些情况是协议上说的不包含IMSI的情况呢? 没有看懂,忘各位指点。 |