Читать книгу Mobile Communications Systems Development - Rajib Taid - Страница 112

In the LTE/EPS and 5G systems, the GTPv2 control plane signaling messages are used in a couple of logical interfaces, for example, between the LTE/EPS MME and the S‐GW and S‐GW and P‐GW. The fifth bit of a GTPv2 control plane header, 3GPP TS 29.274 [70], contains a field called “P” which indicates the presence of a further piggybacked GTPv2C message along with the current GTP GTPv2C messages. For example, a Create Session Response message from the S‐GW to the MME may contain the Create Bearer Request message as well as the piggybacked message for the MME. In this case, the “P” flag in the header of the Create Session Response message shall be set to 1.