03.603GPPGeneral Packet Radio Service (GPRS)Release 1998Service descriptionStage 2TS
This example is almost the same as the previous one. In this case, the MS has roamed to another PLMN and the SGSN that is currently serving the MS is in a visited PLMN while the GGSN is in the home PLMN.
A mobile-terminated GTP PDU is carried from the GGSN to the SGSN via the home intra-PLMN backbone network to the inter-PLMN backbone network and finally to the visited intra-PLMN backbone network.
– The routeing for MO and MT packets can be optimised if the activated PDP address is dynamically assigned by the visited PLMN.
Figure C.2: Data Routeing for a Roaming MS to and from an External PDN