Roaming Peer Detection by Application

SMF supports PLMN-list configuration under the SMF profile. The SMF compares the serving and the UE-PLMN with the configured plmns to decide if the session is homer or roamer.

If the UE-PLMN is found listed in the configured PLMN list and the serving-PLMN is not found in the configured PLMN list, the session is marked as roamer (outbound roamer).

Upon getting a CSR for fresh session create or MBR for handoff, the SMF services detect that the session is a roamer session.

Note

It is assumed that the first downlink control message from SMF to a partner SGW is a Create Session Response or a Modified Bearer Response.