in ran_msg, return gsm0808_speech_codec (intra-MSC)
Do not convert to enum mgcp_codecs, but directly pass the
gsm0808_speech_codec IE from the A interface to codecs handling.
For Iu:
- RAN side: use ran_infra.force_mgw_codecs_to_ran to keep the MGW
endpoint towards RAN on IUFP.
- CN side: introduce flag ran_msg.assignment_complete.codec_with_iuup,
so to decide whether to forward IUFP towards CN, we don't need to test
the RAN type, but use the flag from the ran_msg implementation.
In msc_vlr_tests, use the SDP codec string instead of enum
mgcp_codecs.
So far limit to intra-MSC related messaging, adjusting inter-MSC
handover follows in a separate patch.
Change-Id: Ia666cb697fbd140d7239089628faed93860ce671
diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c
index e9f1840..f1e365f 100644
--- a/src/libmsc/msc_a.c
+++ b/src/libmsc/msc_a.c
@@ -1325,8 +1325,8 @@
{
struct gsm_trans *cc_trans = msc_a->cc.active_trans;
struct rtp_stream *rtps_to_ran = msc_a->cc.call_leg ? msc_a->cc.call_leg->rtp[RTP_TO_RAN] : NULL;
- const enum mgcp_codecs *codec_if_known = ac->assignment_complete.codec_present ?
- &ac->assignment_complete.codec : NULL;
+ const struct gsm0808_speech_codec *codec_if_known = ac->assignment_complete.codec_present ?
+ &ac->assignment_complete.codec : NULL;
const struct codec_mapping *codec_cn = NULL;
if (!rtps_to_ran) {
@@ -1346,16 +1346,33 @@
}
if (codec_if_known) {
- codec_cn = codec_mapping_by_mgcp_codec(*codec_if_known);
- if (!codec_cn) {
- LOG_TRANS(cc_trans, LOGL_ERROR, "Unknown codec in Assignment Complete: %s\n",
- osmo_mgcpc_codec_name(*codec_if_known));
- call_leg_release(msc_a->cc.call_leg);
- return;
+ if (ac->assignment_complete.codec_with_iuup) {
+ /* FUTURE: soon, we want to tell the MGW to decapsulate IuUP to plain AMR-FR/RTP. So far,
+ * continue to forward IuUP to the CN.
+ *
+ * ran_msg_iu now returns AMR-FR as the assigned codec. If we use that directly, that will
+ * instruct the MGW to decapsulate IuUP into plain RTP. Let's keep this change to an explicit
+ * patch, while various codecs patches are still being applied.
+ *
+ * So instruct MGW to forward IuUP to CN:
+ */
+ codec_cn = codec_mapping_by_subtype_name("VND.3GPP.IUFP");
+ OSMO_ASSERT(codec_cn);
+ } else {
+ codec_cn = codec_mapping_by_gsm0808_speech_codec_type(codec_if_known->type);
+ /* TODO: use codec_mapping_by_gsm0808_speech_codec() to also match on codec_if_known->cfg */
+ if (!codec_cn) {
+ LOG_TRANS(cc_trans, LOGL_ERROR, "Unknown codec in Assignment Complete: %s\n",
+ gsm0808_speech_codec_type_name(codec_if_known->type));
+ call_leg_release(msc_a->cc.call_leg);
+ return;
+ }
}
- /* Update RAN-side endpoint CI from Assignment result */
- rtp_stream_set_one_codec(rtps_to_ran, &codec_cn->sdp);
+ /* Update RAN-side endpoint CI from Assignment result -- unless it is forced by the ran_infra, in which
+ * case it remains unchanged as passed to the earlier call of call_leg_ensure_ci(). */
+ if (msc_a->c.ran->force_mgw_codecs_to_ran.count == 0)
+ rtp_stream_set_one_codec(rtps_to_ran, &codec_cn->sdp);
/* Update codec filter with Assignment result, for the CN side */
cc_trans->cc.codecs.assignment = codec_cn->sdp;
diff --git a/src/libmsc/ran_msg_a.c b/src/libmsc/ran_msg_a.c
index c9a13a2..56252f1 100644
--- a/src/libmsc/ran_msg_a.c
+++ b/src/libmsc/ran_msg_a.c
@@ -276,7 +276,6 @@
struct tlv_p_entry *ie_codec_list_bss_supported = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST);
struct tlv_p_entry *ie_osmux_cid = TLVP_GET(tp, GSM0808_IE_OSMO_OSMUX_CID);
struct sockaddr_storage rtp_addr;
- struct gsm0808_speech_codec sc;
struct gsm0808_speech_codec_list codec_list_bss_supported;
int rc;
struct ran_msg ran_dec_msg = {
@@ -309,14 +308,14 @@
if (ie_speech_codec) {
/* Decode Speech Codec (Chosen) element */
- rc = gsm0808_dec_speech_codec(&sc, ie_speech_codec->val, ie_speech_codec->len);
+ rc = gsm0808_dec_speech_codec(&ran_dec_msg.assignment_complete.codec,
+ ie_speech_codec->val, ie_speech_codec->len);
if (rc < 0) {
LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Assignment Complete: unable to decode IE Speech Codec (Chosen)"
" (rc=%d).\n", rc);
return -EINVAL;
}
ran_dec_msg.assignment_complete.codec_present = true;
- ran_dec_msg.assignment_complete.codec = ran_a_mgcp_codec_from_sc(&sc);
}
if (ie_codec_list_bss_supported) {
diff --git a/src/libmsc/ran_msg_iu.c b/src/libmsc/ran_msg_iu.c
index ee1d0a5..eb7fc93 100644
--- a/src/libmsc/ran_msg_iu.c
+++ b/src/libmsc/ran_msg_iu.c
@@ -153,8 +153,16 @@
.msg_type = RAN_MSG_ASSIGNMENT_COMPLETE,
.msg_name = "RANAP RAB Assignment Response",
.assignment_complete = {
+ /* For codec compatibility resolution, indicate AMR-FR */
.codec_present = true,
- .codec = CODEC_IUFP,
+ .codec = {
+ .fi = true,
+ .type = GSM0808_SCT_FR3,
+ .cfg = GSM0808_SC_CFG_DEFAULT_FR_AMR,
+ },
+ /* Indicate that (at least) the first MGW endpoint towards RAN needs to expect VND.3GPP.IUFP
+ * that encapsulates the AMR-FR RTP payload. */
+ .codec_with_iuup = true,
},
};
if (osmo_sockaddr_str_from_str(&ran_dec_msg->assignment_complete.remote_rtp, addr, port)) {