Feature #6151
Updated by pespin 9 months ago
Right now, RAB-ASsignment-Req message is built in osmo-iuh.git and it is hardcoded to built an RFCI list basically containing AMR 12k2. The interesting related code path is: <pre> ran_iu_encode(RAN_MSG_ASSIGNMENT_COMMAND) ran_iu_make_rab_assignment ranap_new_msg_rab_assign_voice [osmo-iuh] new_rab_par_voice new_sdu_par_item </pre> If you check new_sdu_par_item() in osmo-iuh.git (https://gitea.osmocom.org/cellular-infrastructure/osmo-iuh/src/branch/master/src/ranap_msg_factory.c#L556), you can see how the SDUs are added there, hardcoded. Ideally, the RFCI list would be passed to ranap_new_msg_rab_assign_voice() from osmo-msc. Then, from osmo-msc, an RFCI would be built based on: - Whether the UE supports AMR or AMR-WB (CC Setup message, "Supported Codec List" IE) - Whether osmo-msc is configured to serve AMR or/and AMR-WB on the VTY - Whatever other restrictions on the other call leg This would allow, for instance testing IuUP/AMR-WB calls. If AMR-WB is selected, we probably need to update the SDP related paths to add "16000" after IUFP: <pre> a=rtpmap:97 VND.3GPP.IUFP/16000 </pre> Some related specs: * 3GPP TS 25.413 (RANAP) * 3GPP TS 25.415 (IuUP) * 3GPP TS 26.171, 3GPP TS 26.201, 3GPP TS 26.202 (AMR-WB) * RFC 4867 (RTP for AMR, (AMR, AMR-WB)
