diff --git a/include/osmocom/msc/transaction.h b/include/osmocom/msc/transaction.h
index 7ffcf3b..99aca55 100644
--- a/include/osmocom/msc/transaction.h
+++ b/include/osmocom/msc/transaction.h
@@ -6,18 +6,21 @@
 #include <osmocom/core/fsm.h>
 #include <osmocom/msc/gsm_04_11.h>
 #include <osmocom/msc/mncc.h>
+#include <osmocom/msc/msc_a.h>
 #include <osmocom/msc/debug.h>
 #include <osmocom/gsm/gsm0411_smc.h>
 #include <osmocom/gsm/gsm0411_smr.h>
 
+struct vty;
+
 /* Used for late TID assignment */
 #define TRANS_ID_UNASSIGNED 0xff
 
 #define LOG_TRANS_CAT(trans, subsys, level, fmt, args...) \
 	LOGP(subsys, level, \
 	     "trans(%s %s callref-0x%x tid-%u%s) " fmt, \
-	     (trans) ? gsm48_pdisc_name((trans)->protocol) : "NULL", \
-	     (trans) ? ((trans)->conn ? (trans)->conn->fi->id : vlr_subscr_name((trans)->vsub)) : "NULL", \
+	     (trans) ? trans_type_name((trans)->type) : "NULL", \
+	     (trans) ? ((trans)->msc_a ? (trans)->msc_a->c.fi->id : vlr_subscr_name((trans)->vsub)) : "NULL", \
 	     (trans) ? (trans)->callref : 0, \
 	     (trans) ? (trans)->transaction_id : 0, \
 	     (trans) && (trans)->paging_request ? ",PAGING" : "", \
@@ -34,6 +37,19 @@
 	BRIDGE_STATE_BRIDGE_ESTABLISHED,
 };
 
+enum trans_type {
+	TRANS_CC = GSM48_PDISC_CC,
+	TRANS_SMS = GSM48_PDISC_SMS,
+	TRANS_USSD = GSM48_PDISC_NC_SS,
+	TRANS_SILENT_CALL,
+};
+
+extern const struct value_string trans_type_names[];
+static inline const char *trans_type_name(enum trans_type val)
+{ return get_value_string(trans_type_names, val); }
+
+uint8_t trans_type_to_gsm48_proto(enum trans_type type);
+
 /* One transaction */
 struct gsm_trans {
 	/* Entry in list of all transactions */
@@ -42,8 +58,8 @@
 	/* Back pointer to the network struct */
 	struct gsm_network *net;
 
-	/* The protocol within which we live */
-	uint8_t protocol;
+	/* What kind of transaction */
+	enum trans_type type;
 
 	/* The current transaction ID */
 	uint8_t transaction_id;
@@ -55,7 +71,7 @@
 	struct vlr_subscr *vsub;
 
 	/* The associated connection we are using to transmit messages */
-	struct ran_conn *conn;
+	struct msc_a *msc_a;
 
 	/* reference from MNCC or other application */
 	uint32_t callref;
@@ -64,7 +80,7 @@
 	int tch_recv;
 
 	/* is thats one paging? */
-	struct subscr_request *paging_request;
+	struct paging_request *paging_request;
 
 	/* bearer capabilities (rate and codec) */
 	struct gsm_mncc_bearer_cap bearer_cap;
@@ -85,7 +101,6 @@
 			struct osmo_timer_list timer;
 			struct osmo_timer_list timer_guard;
 			struct gsm_mncc msg;	/* stores setup/disconnect/release message */
-			bool assignment_started;
 		} cc;
 		struct {
 			struct gsm411_smc_inst smc_inst;
@@ -105,6 +120,11 @@
 			/* Inactivity timer, triggers transaction release */
 			struct osmo_timer_list timer_guard;
 		} ss;
+		struct {
+			struct gsm0808_channel_type ct;
+			struct osmo_sockaddr_str rtp_cn;
+			struct vty *from_vty;
+		} silent_call;
 	};
 
 	struct {
@@ -115,8 +135,9 @@
 
 
 
-struct gsm_trans *trans_find_by_id(const struct ran_conn *conn,
-				   uint8_t proto, uint8_t trans_id);
+struct gsm_trans *trans_find_by_type(const struct msc_a *msc_a, enum trans_type type);
+struct gsm_trans *trans_find_by_id(const struct msc_a *msc_a,
+				   enum trans_type type, uint8_t trans_id);
 struct gsm_trans *trans_find_by_callref(const struct gsm_network *net,
 					uint32_t callref);
 struct gsm_trans *trans_find_by_sm_rp_mr(const struct gsm_network *net,
@@ -125,26 +146,28 @@
 
 struct gsm_trans *trans_alloc(struct gsm_network *net,
 			      struct vlr_subscr *vsub,
-			      uint8_t protocol, uint8_t trans_id,
+			      enum trans_type type, uint8_t trans_id,
 			      uint32_t callref);
 void trans_free(struct gsm_trans *trans);
 
 int trans_assign_trans_id(const struct gsm_network *net, const struct vlr_subscr *vsub,
-			  uint8_t protocol);
-struct gsm_trans *trans_has_conn(const struct ran_conn *conn);
-void trans_conn_closed(const struct ran_conn *conn);
+			  enum trans_type type);
+struct gsm_trans *trans_has_conn(const struct msc_a *msc_a);
+void trans_conn_closed(const struct msc_a *msc_a);
 
 static inline int trans_log_subsys(const struct gsm_trans *trans)
 {
 	if (!trans)
 		return DMSC;
-	switch (trans->protocol) {
-	case GSM48_PDISC_CC:
+	switch (trans->type) {
+	case TRANS_CC:
 		return DCC;
-	case GSM48_PDISC_SMS:
+	case TRANS_SMS:
 		return DLSMS;
 	default:
 		break;
 	}
+	if (trans->msc_a)
+		return trans->msc_a->c.ran->log_subsys;
 	return DMSC;
 }