[layer23] Speech codec selection and negotiation with network

6 files changed, 412 insertions, 32 deletions

diff --git a/src/host/layer23/src/mobile/gsm48_cc.c b/src/host/layer23/src/mobile/gsm48_cc.c
index 4b8db53e..a58f627a 100644
--- a/src/host/layer23/src/mobile/gsm48_cc.c
+++ b/src/host/layer23/src/mobile/gsm48_cc.c
@@ -550,9 +550,10 @@ static int gsm48_cc_tx_setup(struct gsm_trans *trans)
 	 */
 	gsm48_start_cc_timer(trans, 0x303, GSM48_T303_MS);
 
-	if (!setup->emergency) {
-		/* bearer capability */
+	/* bearer capability (optional for emergency calls only) */
+	if (setup->fields & MNCC_F_BEARER_CAP)
 		gsm48_encode_bearer_cap(nmsg, 0, &setup->bearer_cap);
+	if (!setup->emergency) {
 		/* facility */
 		if (setup->fields & MNCC_F_FACILITY)
 			gsm48_encode_facility(nmsg, 0, &setup->facility);
diff --git a/src/host/layer23/src/mobile/gsm48_rr.c b/src/host/layer23/src/mobile/gsm48_rr.c
index 333b379b..656d4c2b 100644
--- a/src/host/layer23/src/mobile/gsm48_rr.c
+++ b/src/host/layer23/src/mobile/gsm48_rr.c
@@ -86,6 +86,8 @@ static void stop_rr_t3124(struct gsm48_rrlayer *rr);
 static int gsm48_rcv_rsl(struct osmocom_ms *ms, struct msgb *msg);
 static int gsm48_rr_dl_est(struct osmocom_ms *ms);
 static int gsm48_rr_tx_meas_rep(struct osmocom_ms *ms);
+static int gsm48_rr_set_mode(struct osmocom_ms *ms, uint8_t chan_nr,
+	uint8_t mode);
 
 /*
  * support
@@ -278,6 +280,79 @@ static int gsm48_apply_v_sd(struct gsm48_rrlayer *rr, struct msgb *msg)
 	return 0;
 }
 
+/* set channel mode if supported, or return error cause */
+static uint8_t gsm48_rr_check_mode(struct osmocom_ms *ms, uint8_t chan_nr,
+	uint8_t mode)
+{
+	struct gsm_support *sup = &ms->support;
+	uint8_t ch_type, ch_subch, ch_ts;
+
+	/* only complain if we use TCH/F or TCH/H */
+	rsl_dec_chan_nr(chan_nr, &ch_type, &ch_subch, &ch_ts);
+	if (ch_type != RSL_CHAN_Bm_ACCHs
+	 && ch_type != RSL_CHAN_Lm_ACCHs)
+		return 0;
+
+	switch (mode) {
+	case GSM48_CMODE_SIGN:
+		LOGP(DRR, LOGL_INFO, "Mode: signalling\n");
+		break;
+	case GSM48_CMODE_SPEECH_V1:
+		if (ch_type == RSL_CHAN_Bm_ACCHs) {
+			if (!sup->full_v1) {
+				LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"full-rate speech V1\n");
+				return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+			}
+			LOGP(DRR, LOGL_INFO, "Mode: full-rate speech V1\n");
+		} else {
+			if (!sup->half_v1) {
+				LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"half-rate speech V1\n");
+				return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+			}
+			LOGP(DRR, LOGL_INFO, "Mode: half-rate speech V1\n");
+		}
+		break;
+	case GSM48_CMODE_SPEECH_EFR:
+		if (ch_type == RSL_CHAN_Bm_ACCHs) {
+			if (!sup->full_v2) {
+				LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"full-rate speech V2\n");
+				return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+			}
+			LOGP(DRR, LOGL_INFO, "Mode: full-rate speech V2\n");
+		} else {
+			LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"half-rate speech V2\n");
+			return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+		}
+		break;
+	case GSM48_CMODE_SPEECH_AMR:
+		if (ch_type == RSL_CHAN_Bm_ACCHs) {
+			if (!sup->full_v3) {
+				LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"full-rate speech V3\n");
+				return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+			}
+			LOGP(DRR, LOGL_INFO, "Mode: full-rate speech V3\n");
+		} else {
+			if (!sup->half_v3) {
+				LOGP(DRR, LOGL_NOTICE, "Not supporting "
+					"half-rate speech V3\n");
+				return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+			}
+			LOGP(DRR, LOGL_INFO, "Mode: half-rate speech V3\n");
+		}
+		break;
+	default:
+		LOGP(DRR, LOGL_ERROR, "Mode 0x%02x not supported!\n", mode);
+		return GSM48_RR_CAUSE_CHAN_MODE_UNACCT;
+	}
+
+	return 0;
+}
+
 /*
  * state transition
  */
@@ -883,7 +958,7 @@ static int gsm48_rr_rx_cip_mode_cmd(struct osmocom_ms *ms, struct msgb *msg)
 		|| (alg_id == GSM_CIPHER_A5_7 && !sup->a5_7))) {
 		LOGP(DRR, LOGL_NOTICE, "algo not supported\n");
 		return gsm48_rr_tx_rr_status(ms,
-			GSM48_RR_CAUSE_CHAN_MODE_UNACCT);
+			GSM48_RR_CAUSE_PROT_ERROR_UNSPC);
 	}
 
 	/* check if we have no key */
@@ -3093,7 +3168,8 @@ static int gsm48_rr_activate_channel(struct osmocom_ms *ms,
 
 	if (rr->cipher_on)
 		l1ctl_tx_crypto_req(ms, rr->cipher_type + 1, subscr->key, 8);
-#warning FIXME: channel mode
+
+	gsm48_rr_set_mode(ms, cd->chan_nr, cd->mode);
 
 	return 0;
 }
@@ -3113,7 +3189,8 @@ static int gsm48_rr_channel_after_time(struct osmocom_ms *ms,
 
 	if (rr->cipher_on)
 		l1ctl_tx_crypto_req(ms, rr->cipher_type + 1, subscr->key, 8);
-#warning FIXME: channel mode
+
+	gsm48_rr_set_mode(ms, cd->chan_nr, cd->mode);
 
 	return 0;
 }
@@ -3473,6 +3550,25 @@ static int gsm48_rr_rx_chan_rel(struct osmocom_ms *ms, struct msgb *msg)
  * frequency redefition, chanel mode modify, assignment, and handover
  */
 
+/* set channel mode in case of TCH */
+static int gsm48_rr_set_mode(struct osmocom_ms *ms, uint8_t chan_nr,
+	uint8_t mode)
+{
+	uint8_t ch_type, ch_subch, ch_ts;
+
+	/* only apply mode to TCH/F or TCH/H */
+	rsl_dec_chan_nr(chan_nr, &ch_type, &ch_subch, &ch_ts);
+	if (ch_type != RSL_CHAN_Bm_ACCHs
+	 && ch_type != RSL_CHAN_Lm_ACCHs)
+		return -ENOTSUP;
+
+	/* setting (new) timing advance */
+	LOGP(DRR, LOGL_INFO, "setting TCH mode to %d\n", mode);
+	l1ctl_tx_tch_mode_req(ms, mode);
+
+	return 0;
+}
+
 /* 9.1.13 FREQUENCY REDEFINITION is received */
 static int gsm48_rr_rx_frq_redef(struct osmocom_ms *ms, struct msgb *msg)
 {
@@ -3589,7 +3685,7 @@ static int gsm48_rr_rx_chan_modify(struct osmocom_ms *ms, struct msgb *msg)
 	int payload_len = msgb_l3len(msg) - sizeof(*gh) - sizeof(*cm);
 	struct gsm48_rr_cd *cd = &rr->cd_now;
 	uint8_t ch_type, ch_subch, ch_ts;
-	uint8_t mode;
+	uint8_t cause;
 
 	LOGP(DRR, LOGL_INFO, "CHANNEL MODE MODIFY\n");
 
@@ -3619,21 +3715,13 @@ static int gsm48_rr_rx_chan_modify(struct osmocom_ms *ms, struct msgb *msg)
 			ch_ts, ch_subch, cd->tsc, cm->mode);
 	}
 	/* mode */
-	mode = cm->mode;
-	switch (mode) {
-	case GSM48_CMODE_SIGN:
-		LOGP(DRR, LOGL_INFO, "Mode set to signalling.\n");
-		break;
-	case GSM48_CMODE_SPEECH_V1:
-		LOGP(DRR, LOGL_INFO, "Mode set to GSM full-rate codec.\n");
-		break;
-	default:
-		LOGP(DRR, LOGL_ERROR, "Mode %u not supported!\n", mode);
-	}
-	rr->cd_now.mode = mode;
-#warning FIXME: channel mode
+	cause = gsm48_rr_check_mode(ms, cd->chan_nr, cm->mode);
+	if (cause)
+		return gsm48_rr_tx_rr_status(ms, cause);
+	cd->mode = cm->mode;
+	gsm48_rr_set_mode(ms, cd->chan_nr, cd->mode);
 
-	return gsm48_rr_tx_chan_modify_ack(ms, &cm->chan_desc, mode);
+	return gsm48_rr_tx_chan_modify_ack(ms, &cm->chan_desc, cm->mode);
 }
 
 /* 9.1.3 sending ASSIGNMENT COMPLETE */
@@ -3860,6 +3948,7 @@ static int gsm48_rr_rx_ass_cmd(struct osmocom_ms *ms, struct msgb *msg)
 				"mobile allocation after time\n");
 			memcpy(&cdb->mob_alloc_lv, &cda->mob_alloc_lv,
 				sizeof(cdb->mob_alloc_lv));
+		} else
 		if (cda->freq_list_lv[0]) {
 			LOGP(DRR, LOGL_INFO, " before: hopping required and "
 				"frequency list not available, using "
@@ -3901,7 +3990,7 @@ static int gsm48_rr_rx_ass_cmd(struct osmocom_ms *ms, struct msgb *msg)
 		cda->mode = cdb->mode = rr->cd_now.mode;
 
 	/* cipher mode setting */
-	if (TLVP_PRESENT(&tp, GSM48_IE_CIP_MODE_SET))
+	if (TLVP_PRESENT(&tp, GSM48_IE_CIP_MODE_SET)) {
 		cda->cipher = cdb->cipher =
 			*TLVP_VAL(&tp, GSM48_IE_CIP_MODE_SET);
 		LOGP(DRR, LOGL_INFO, " both: changing cipher mode 0x%02x\n",
@@ -3943,6 +4032,9 @@ static int gsm48_rr_rx_ass_cmd(struct osmocom_ms *ms, struct msgb *msg)
 	}
 
 	/* check if channels are valid */
+	cause = gsm48_rr_check_mode(ms, cda->chan_nr, cda->mode);
+	if (cause)
+		return gsm48_rr_tx_ass_fail(ms, cause);
 	if (before_time) {
 		cause = gsm48_rr_render_ma(ms, cdb, ma, &ma_len);
 		if (cause)
@@ -4231,6 +4323,7 @@ static int gsm48_rr_rx_hando_cmd(struct osmocom_ms *ms, struct msgb *msg)
 				"mobile allocation after time\n");
 			memcpy(&cdb->mob_alloc_lv, &cda->mob_alloc_lv,
 				sizeof(cdb->mob_alloc_lv));
+		} else
 		if (cda->freq_list_lv[0]) {
 			LOGP(DRR, LOGL_INFO, " before: hopping required and "
 				"frequency list not available, using "
@@ -4272,7 +4365,7 @@ static int gsm48_rr_rx_hando_cmd(struct osmocom_ms *ms, struct msgb *msg)
 		cda->mode = cdb->mode = rr->cd_now.mode;
 
 	/* cipher mode setting */
-	if (TLVP_PRESENT(&tp, GSM48_IE_CIP_MODE_SET))
+	if (TLVP_PRESENT(&tp, GSM48_IE_CIP_MODE_SET)) {
 		cda->cipher = cdb->cipher =
 			*TLVP_VAL(&tp, GSM48_IE_CIP_MODE_SET);
 		LOGP(DRR, LOGL_INFO, " both: changing cipher mode 0x%02x\n",
diff --git a/src/host/layer23/src/mobile/mnccms.c b/src/host/layer23/src/mobile/mnccms.c
index 6940ed12..9aeaf4dc 100644
--- a/src/host/layer23/src/mobile/mnccms.c
+++ b/src/host/layer23/src/mobile/mnccms.c
@@ -61,6 +61,117 @@ struct gsm_call *get_call_ref(uint32_t callref)
 	return NULL;
 }
 
+static int8_t mncc_get_bearer(struct gsm_support *sup, uint8_t speech_ver)
+{
+	switch (speech_ver) {
+	case 4:
+		if (sup->full_v3)
+			LOGP(DMNCC, LOGL_INFO, " net suggests full rate v3\n");
+		else {
+			LOGP(DMNCC, LOGL_INFO, " full rate v3 not supported\n");
+			speech_ver = -1;
+		}
+		break;
+	case 2:
+		if (sup->full_v2)
+			LOGP(DMNCC, LOGL_INFO, " net suggests full rate v2\n");
+		else {
+			LOGP(DMNCC, LOGL_INFO, " full rate v2 not supported\n");
+			speech_ver = -1;
+		}
+		break;
+	case 0: /* mandatory */
+		if (sup->full_v1)
+			LOGP(DMNCC, LOGL_INFO, " net suggests full rate v1\n");
+		else {
+			LOGP(DMNCC, LOGL_INFO, " full rate v1 not supported\n");
+			speech_ver = -1;
+		}
+		break;
+	case 5:
+		if (sup->half_v3)
+			LOGP(DMNCC, LOGL_INFO, " net suggests half rate v3\n");
+		else {
+			LOGP(DMNCC, LOGL_INFO, " half rate v3 not supported\n");
+			speech_ver = -1;
+		}
+		break;
+	case 1:
+		if (sup->half_v1)
+			LOGP(DMNCC, LOGL_INFO, " net suggests half rate v1\n");
+		else {
+			LOGP(DMNCC, LOGL_INFO, " half rate v1 not supported\n");
+			speech_ver = -1;
+		}
+		break;
+	default:
+		LOGP(DMNCC, LOGL_INFO, " net suggests unknown speech version "
+			"%d\n", speech_ver);
+		speech_ver = -1;
+	}
+
+	return speech_ver;
+}
+
+static void mncc_set_bearer(struct osmocom_ms *ms, int8_t speech_ver,
+	struct gsm_mncc *mncc)
+{
+	struct gsm_support *sup = &ms->support;
+	struct gsm_settings *set = &ms->settings;
+	int i = 0;
+
+	mncc->fields |= MNCC_F_BEARER_CAP;
+	mncc->bearer_cap.coding = 0;
+	if (sup->ch_cap == GSM_CAP_SDCCH_TCHF_TCHH
+	 && (sup->half_v1 || sup->half_v3)) {
+		mncc->bearer_cap.radio = 3;
+		LOGP(DMNCC, LOGL_INFO, " support TCH/H also\n");
+	} else {
+		mncc->bearer_cap.radio = 1;
+		LOGP(DMNCC, LOGL_INFO, " support TCH/F only\n");
+	}
+	mncc->bearer_cap.speech_ctm = 0;
+	/* if no specific speech_ver is given */
+	if (speech_ver < 0) {
+		/* if half rate is supported and prefered */
+		if (sup->half_v3 && set->half && set->half_prefer) {
+			mncc->bearer_cap.speech_ver[i++] = 5;
+			LOGP(DMNCC, LOGL_INFO, " support half rate v3\n");
+		}
+		if (sup->half_v1 && set->half && set->half_prefer) {
+			mncc->bearer_cap.speech_ver[i++] = 1;
+			LOGP(DMNCC, LOGL_INFO, " support half rate v1\n");
+		}
+		/* if full rate is supported */
+		if (sup->full_v3) {
+			mncc->bearer_cap.speech_ver[i++] = 4;
+			LOGP(DMNCC, LOGL_INFO, " support full rate v3\n");
+		}
+		if (sup->full_v2) {
+			mncc->bearer_cap.speech_ver[i++] = 2;
+			LOGP(DMNCC, LOGL_INFO, " support full rate v2\n");
+		}
+		if (sup->full_v1) { /* mandatory, so it's always true */
+			mncc->bearer_cap.speech_ver[i++] = 0;
+			LOGP(DMNCC, LOGL_INFO, " support full rate v1\n");
+		}
+		/* if half rate is supported and not prefered */
+		if (sup->half_v3 && set->half && !set->half_prefer) {
+			mncc->bearer_cap.speech_ver[i++] = 5;
+			LOGP(DMNCC, LOGL_INFO, " support half rate v3\n");
+		}
+		if (sup->half_v1 && set->half && !set->half_prefer) {
+			mncc->bearer_cap.speech_ver[i++] = 1;
+			LOGP(DMNCC, LOGL_INFO, " support half rate v1\n");
+		}
+	/* if specific speech_ver is given (it must be supported) */
+	} else 
+		mncc->bearer_cap.speech_ver[i++] = speech_ver;
+	mncc->bearer_cap.speech_ver[i] = -1; /* end of list */
+	mncc->bearer_cap.transfer = 0;
+	mncc->bearer_cap.mode = 0;
+}
+
 /*
  * MNCCms dummy application
  */
@@ -92,10 +203,13 @@ int mncc_recv_dummy(struct osmocom_ms *ms, int msg_type, void *arg)
 
 int mncc_recv_mobile(struct osmocom_ms *ms, int msg_type, void *arg)
 {
+	struct gsm_settings *set = &ms->settings;
+	struct gsm_support *sup = &ms->support;
 	struct gsm_mncc *data = arg;
 	struct gsm_call *call = get_call_ref(data->callref);
 	struct gsm_mncc mncc;
 	uint8_t cause;
+	int8_t	speech_ver = -1, speech_ver_half = -1, temp;
 	int first_call = 0;
 
 	/* call does not exist */
@@ -203,6 +317,10 @@ int mncc_recv_mobile(struct osmocom_ms *ms, int msg_type, void *arg)
 		vty_notify(ms, NULL);
 		vty_notify(ms, "Call is proceeding\n");
 		LOGP(DMNCC, LOGL_INFO, "Call is proceeding\n");
+		if ((data->fields & MNCC_F_BEARER_CAP)
+		 && data->bearer_cap.speech_ver[0] >= 0) {
+			mncc_get_bearer(sup, data->bearer_cap.speech_ver[0]);
+		}
 		break;
 	case MNCC_ALERT_IND:
 		vty_notify(ms, NULL);
@@ -222,6 +340,59 @@ int mncc_recv_mobile(struct osmocom_ms *ms, int msg_type, void *arg)
 			cause = GSM48_CC_CAUSE_USER_BUSY;
 			goto release;
 		}
+		/* select first supported speech_ver */
+		if ((data->fields & MNCC_F_BEARER_CAP)) {
+			int i;
+
+			for (i = 0; data->bearer_cap.speech_ver[i] >= 0; i++) {
+
+				temp = mncc_get_bearer(sup,
+					data->bearer_cap.speech_ver[i]);
+				if (temp < 0)
+					continue;
+				if (temp == 5 || temp == 1) { /* half */
+					/* only the first half rate */
+					if (speech_ver_half < 0)
+						speech_ver_half = temp;
+				} else {
+					/* only the first full rate */
+					if (speech_ver < 0)
+						speech_ver = temp;
+				}
+			}
+			/* half and full given */
+			if (speech_ver_half >= 0 && speech_ver >= 0) {
+				if (set->half_prefer) {
+					LOGP(DMNCC, LOGL_INFO, " both supported"
+						" codec rates are given, using "
+						"preferred half rate\n");
+					speech_ver = speech_ver_half;
+				} else
+					LOGP(DMNCC, LOGL_INFO, " both supported"
+						" codec rates are given, using "
+						"preferred full rate\n");
+			} else if (speech_ver_half < 0 && speech_ver < 0) {
+				LOGP(DMNCC, LOGL_INFO, " no supported codec "
+					"rate is given\n");
+			/* only half rate is given, use it */
+			} else if (speech_ver_half >= 0) {
+				LOGP(DMNCC, LOGL_INFO, " only supported half "
+					"rate codec is given, using it\n");
+				speech_ver = speech_ver_half;
+			/* only full rate is given, use it */
+			} else {
+				LOGP(DMNCC, LOGL_INFO, " only supported full "
+					"rate codec is given, using it\n");
+			}
+			if (speech_ver < 0) {
+				vty_notify(ms, "Incomming call rejected, no "
+					"voice call\n");
+				LOGP(DMNCC, LOGL_INFO, "Incomming call "
+					"rejected, no voice call\n");
+				cause = GSM48_CC_CAUSE_BEARERSERV_UNIMPL;
+				goto release;
+			}
+		}
 		/* presentation allowed if present == 0 */
 		if (data->calling.present || !data->calling.number[0])
 			vty_notify(ms, "Incomming call (anonymous)\n");
@@ -238,6 +409,16 @@ int mncc_recv_mobile(struct osmocom_ms *ms, int msg_type, void *arg)
 			data->calling.number, call->callref);
 		memset(&mncc, 0, sizeof(struct gsm_mncc));
 		mncc.callref = call->callref;
+		/* only include bearer cap, if not given in setup
+		 * or if multiple codecs are given
+		 * or if not only full rate
+		 * or if given codec is unimplemented
+		 */
+		if (!(data->fields & MNCC_F_BEARER_CAP) || speech_ver < 0)
+			mncc_set_bearer(ms, -1, &mncc);
+		else if (data->bearer_cap.speech_ver[1] >= 0
+		      || speech_ver != 0)
+			mncc_set_bearer(ms, speech_ver, &mncc);
 		mncc_send(ms, MNCC_CALL_CONF_REQ, &mncc);
 		if (first_call)
 			LOGP(DMNCC, LOGL_INFO, "Ring!\n");
@@ -324,20 +505,13 @@ int mncc_call(struct osmocom_ms *ms, char *number)
 			setup.called.type = 1; /* international */
 		} else
 			setup.called.type = 0; /* auto/unknown - prefix must be
-				 		  used */
+						  used */
 		setup.called.plan = 1; /* ISDN */
 		strncpy(setup.called.number, number,
 			sizeof(setup.called.number) - 1);
 		
 		/* bearer capability (mandatory) */
-		setup.fields |= MNCC_F_BEARER_CAP;
-		setup.bearer_cap.coding = 0;
-		setup.bearer_cap.radio = 1;
-		setup.bearer_cap.speech_ctm = 0;
-		setup.bearer_cap.speech_ver[0] = 0;
-		setup.bearer_cap.speech_ver[1] = -1; /* end of list */
-		setup.bearer_cap.transfer = 0;
-		setup.bearer_cap.mode = 0;
+		mncc_set_bearer(ms, -1, &setup);
 		if (ms->settings.clir)
 			setup.clir.sup = 1;
 		else if (ms->settings.clip)
diff --git a/src/host/layer23/src/mobile/settings.c b/src/host/layer23/src/mobile/settings.c
index 1aef48b0..6b6a9325 100644
--- a/src/host/layer23/src/mobile/settings.c
+++ b/src/host/layer23/src/mobile/settings.c
@@ -31,6 +31,7 @@
 int gsm_settings_init(struct osmocom_ms *ms)
 {
 	struct gsm_settings *set = &ms->settings;
+	struct gsm_support *sup = &ms->support;
 
 	/* IMEI */
 	sprintf(set->imei,   "000000000000000");
@@ -40,6 +41,9 @@ int gsm_settings_init(struct osmocom_ms *ms)
 	strcpy(set->test_imsi, "001010000000000");
 	set->test_rplmn_mcc = set->test_rplmn_mnc = 1;
 
+	if (sup->half_v1 || sup->half_v3)
+		set->half = 1;
+
 	return 0;
 }
 
diff --git a/src/host/layer23/src/mobile/support.c b/src/host/layer23/src/mobile/support.c
index 3fd581d9..631fd5bf 100644
--- a/src/host/layer23/src/mobile/support.c
+++ b/src/host/layer23/src/mobile/support.c
@@ -104,6 +104,13 @@ void gsm_support_init(struct osmocom_ms *ms)
 	sup->min_rxlev_db = -100; // TODO
 	sup->sync_to = 6; /* how long to wait sync (0.9 s) */
 	sup->scan_to = 4; /* how long to wait for all sysinfos (>=4 s) */
+
+	/* codec */
+	sup->full_v1 = 1;
+	sup->full_v2 = 1;
+	sup->full_v3 = 0;
+	sup->half_v1 = 0;
+	sup->half_v3 = 0;
 }
 
 /* (3.2.1) maximum channels to scan within each band */
diff --git a/src/host/layer23/src/mobile/vty_interface.c b/src/host/layer23/src/mobile/vty_interface.c
index 366094f7..eda2d81f 100644
--- a/src/host/layer23/src/mobile/vty_interface.c
+++ b/src/host/layer23/src/mobile/vty_interface.c
@@ -756,6 +756,7 @@ DEFUN(cfg_ms, cfg_ms_cmd, "ms MS_NAME",
 
 static void config_write_ms_single(struct vty *vty, struct osmocom_ms *ms)
 {
+	struct gsm_support *sup = &ms->support;
 	struct gsm_settings *set = &ms->settings;
 
 	vty_out(vty, "ms %s%s", ms->name, VTY_NEWLINE);
@@ -833,6 +834,20 @@ static void config_write_ms_single(struct vty *vty, struct osmocom_ms *ms)
 		vty_out(vty, " no location-updating%s", VTY_NEWLINE);
 	else
 		vty_out(vty, " location-updating%s", VTY_NEWLINE);
+	if (sup->full_v1 || sup->full_v2 || sup->full_v3) {
+		/* mandatory anyway */
+		vty_out(vty, " codec full-speed%s%s",
+			(!set->half_prefer) ? " prefer" : "",
+			VTY_NEWLINE);
+	}
+	if (sup->half_v1 || sup->half_v3) {
+		if (set->half)
+			vty_out(vty, " codec half-speed%s%s",
+				(set->half_prefer) ? " prefer" : "",
+				VTY_NEWLINE);
+		else
+			vty_out(vty, " no codec half-speed%s", VTY_NEWLINE);
+	}
 	vty_out(vty, "exit%s", VTY_NEWLINE);
 	vty_out(vty, "!%s", VTY_NEWLINE);
 }
@@ -1130,6 +1145,88 @@ DEFUN(cfg_ms_no_lupd, cfg_ms_no_lupd_cmd, "no location-updating",
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_codec_full, cfg_ms_codec_full_cmd, "codec full-speed",
+	"Enable codec\nFull speed speech codec")
+{
+	struct osmocom_ms *ms = vty->index;
+	struct gsm_support *sup = &ms->support;
+
+	if (!sup->full_v1 && !sup->full_v2 && !sup->full_v3) {
+		vty_out(vty, "Full-rate codec not supported%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_codec_full_pref, cfg_ms_codec_full_pref_cmd, "codec full-speed "
+	"prefer",
+	"Enable codec\nFull speed speech codec\nPrefer this codec")
+{
+	struct osmocom_ms *ms = vty->index;
+	struct gsm_support *sup = &ms->support;
+
+	if (!sup->full_v1 && !sup->full_v2 && !sup->full_v3) {
+		vty_out(vty, "Full-rate codec not supported%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	ms->settings.half_prefer = 0;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_codec_half, cfg_ms_codec_half_cmd, "codec half-speed",
+	"Enable codec\nHalf speed speech codec")
+{
+	struct osmocom_ms *ms = vty->index;
+	struct gsm_support *sup = &ms->support;
+
+	if (!sup->half_v1 && !sup->half_v3) {
+		vty_out(vty, "Half-rate codec not supported%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	ms->settings.half = 1;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_codec_half_pref, cfg_ms_codec_half_pref_cmd, "codec half-speed "
+	"prefer",
+	"Enable codec\nHalf speed speech codec\nPrefer this codec")
+{
+	struct osmocom_ms *ms = vty->index;
+	struct gsm_support *sup = &ms->support;
+
+	if (!sup->half_v1 && !sup->half_v3) {
+		vty_out(vty, "Half-rate codec not supported%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	ms->settings.half = 1;
+	ms->settings.half_prefer = 1;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_codec_half, cfg_ms_no_codec_half_cmd, "no codec half-speed",
+	NO_STR "Disable codec\nHalf speed speech codec")
+{
+	struct osmocom_ms *ms = vty->index;
+	struct gsm_support *sup = &ms->support;
+
+	if (!sup->half_v1 && !sup->half_v3) {
+		vty_out(vty, "Half-rate codec not supported%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	ms->settings.half = 0;
+	ms->settings.half_prefer = 0;
+
+	return CMD_SUCCESS;
+}
+
 /* per testsim config */
 DEFUN(cfg_ms_testsim, cfg_ms_testsim_cmd, "test-sim",
 	"Configure test SIM emulation")
@@ -1409,7 +1506,11 @@ int ms_vty_init(void)
 	install_element(MS_NODE, &cfg_ms_no_stick_cmd);
 	install_element(MS_NODE, &cfg_ms_lupd_cmd);
 	install_element(MS_NODE, &cfg_ms_no_lupd_cmd);
-
+	install_element(MS_NODE, &cfg_ms_codec_full_cmd);
+	install_element(MS_NODE, &cfg_ms_codec_full_pref_cmd);
+	install_element(MS_NODE, &cfg_ms_codec_half_cmd);
+	install_element(MS_NODE, &cfg_ms_codec_half_pref_cmd);
+	install_element(MS_NODE, &cfg_ms_no_codec_half_cmd);
 	install_node(&testsim_node, config_write_dummy);
 	install_default(TESTSIM_NODE);
 	install_element(TESTSIM_NODE, &ournode_exit_cmd);