diff --git a/src/csl_cha_cco.c b/src/csl_cha_cco.c
index 0eee301..7195876 100644
--- a/src/csl_cha_cco.c
+++ b/src/csl_cha_cco.c
@@ -1,9 +1,59 @@
 /* ITU-T Q.77x TCAP / CCO - Component CoOrdinator
  * part of CHA (ComponentHAndling), part of CSL (Component Sub-Layer) */
 
-/* TC-INVOKE.req (TCU -> CHA) */
-int tcap_cha_tc_invoke_req()
+int tcap_tc_invoke_req(uint32_t dialogue_id, uint8_t class, int8_t inv_id,
+			int8_t *linked_id, struct OPERATION *op,
+			uint8_t *param, uint32_t param_len, uint32_t timeout)
 {
+	struct tcap_dialogue *td;
+
+	td = tcap_dialg_by_dialg_id(dialogue_id);
+	if (!td)
+		td = tcap_dialg_alloc(dialogue_id);
+	if (!td)
+		return -ENOMEM;
+
+	return tcap_cha_tc_invoke_req(td, class, inv_id, linked_id, op, param, param_len, timeout);
+}
+
+/* TC-INVOKE.req (TCU -> CHA) */
+int tcap_cha_tc_invoke_req(struct tcap_dialogue *td, uint8_t class, int8_t inv_id,
+			   int8_t *linked_id, struct OPERATION *op,
+			   uint8_t *param, uint32_t param_len, uint32_t timeout)
+{
+	struct tcap_invocation *ti = tcap_ism_alloc(td, inv_id);
+	struct Component *comp;
+	struct Invoke *inv;
+
+	if (!ti)
+		return -ENOMEM;
+
+	if (linked_id)
+		ti->linked_id = *linked_id;
+
+	/* Allocate a new component structure */
+	comp = talloc_zero(ti, struct Component);
+	comp->present = Component_PR_invoke;
+
+	/* Assemble INV component */
+	inv = &comp->choice.invoke;
+	inv->inv_timeout = timeout;
+	inv->invokeID = ti->invoke_id;
+	if (ti->linked_id != TCAP_INV_LINKED_NONE) {
+		InvokeIdType_t *lid = talloc_zero(inv, InvokeIdType_t);
+		*lid = ti->linked_id;
+		inv->linkedID = lid;
+	}
+	inv->opCode = op;
+	if (param && param_len) {
+		Parameter_t *p = talloc_zero(inv, Parameter_t)
+		p->buf = param;
+		p->size = param_len;
+		inv->parameter = p;
+	}
+	/* FIXME: Make component available for this Dialogue ID */
+
+	return 0;
 }
 
 /* TC-U-CANCEL.req (TCU -> CHA) */
@@ -22,6 +72,43 @@ int tcap_cha_dialg_term(struct tcap_dialogue *td)
 	}
 }
 
+
+/* TC-RESULT-NL / TC-RESULT-L req (TCL -> CHA) */
+int tcap_cha_tc_result_l_req(struct tcap_dialogue *td, int8_t inv_id, int last,
+			     struct OPERATION *op, uint8_t *param, uint32_t param_len)
+{
+	struct tcap_invocation *ti = tcap_ism_by_inv_id(td, inv_id);
+	struct Component *comp;
+	struct returnResult *res;
+	struct resultretres *retres;
+
+	if (!ti)
+		return -EINVAL;
+
+	/* Allocate a new component structure */
+	comp = talloc_zero(ti, struct Component);
+
+	/* Assemble requested component */
+	if (last) {
+		comp->present = Component_PR_returnResultLast;
+		res = &comp->choice.returnResultLast;
+	} else {
+		comp->present = Component_PR_returnResultNotLast;
+		res = &comp->choice.returnResultNotLast;
+	}
+	res->invokeID = ti->invoke_id;
+	retres = talloc_zero(comp, struct resultretres);
+	res->resultretres = retres;
+	retres->opCode = op;
+	if (param && param_len) {
+		Parameter_t *p = talloc_zero(comp, Parameter_t)
+		p->buf = param;
+		p->size = param_len;
+		retres->parameter = p;
+	}
+	/* FIXME: Mark component available for this dialogue ID */
+}
+
 /* TC-RESULT-NL / TC-RESULT-L / TC-U-ERROR request TCL -> CHA */
 {
 	/* Assemble requested component */
diff --git a/src/csl_cha_ism.c b/src/csl_cha_ism.c
index c34d068..58ae0e7 100644
--- a/src/csl_cha_ism.c
+++ b/src/csl_cha_ism.c
@@ -13,7 +13,7 @@ struct tcap_invocation *tcap_ism_lookup(struct tcap_dialogue *td, int8_t invoke_
 
 struct tcap_invocation *tcap_ism_alloc(struct tcap_dialogue *td, int8_t invoke_id)
 {
-	struct tcap_invocation *ti = talloc_zero(tall_tcap_ism_ctx, struct tcap_invocation);
+	struct tcap_invocation *ti = talloc_zero(td, struct tcap_invocation);
 	if (!ti)
 		return NULL;
 	ti->invoke_id = invoke_id;
diff --git a/src/csl_dha.c b/src/csl_dha.c
index ef8e18a..cf6ede6 100644
--- a/src/csl_dha.c
+++ b/src/csl_dha.c
@@ -51,10 +51,13 @@ int tcap_csl_tr_uni_ind()
 	/* Free Dialogue ID */
 }
 
-/* TR-BEGIN.ind from TSL */
-int tcap_csl_tr_beg_ind()
+/* TR-BEGIN.ind from TSL(TSM) -> CSL(DHA) */
+int tcap_csl_tr_begin_ind(struct TCMessage *tcmsg)
 {
-	if (dialogue) {
+	struct Begin *bgmsg = &tcmsg.choice.begin;
+	struct tcap_dialogue *td = td_alloc();
+
+	if (bgmsg->dialoguePortion) {
 		/* extract dialogue portion */
 		if (0/* Check for correctness */) {
 			/* Build ABORT apdu */
@@ -76,7 +79,7 @@ int tcap_csl_tr_beg_ind()
 	/* Assign Dialogue ID */
 	/* TC-BEGIN.ind to TCU */
 	rc = tcap_tcu_begin_ind(td, app_ctx_name, user_info, com_present);
-	if (components) {
+	if (bgmsg->components) {
 		/* Components to CHA */
 	}
 	state = INIT_RECV;
@@ -174,11 +177,13 @@ int tcap_csl_tc_u_abort_req(struct tcap_dialogue *td, uint32_t *abrt_reason, voi
 }
 
 /* TR-END.ind from TSL */
-int tcap_csl_tc_end_ind(struct tcap_dialogue *td)
+int tcap_csl_tr_end_ind(struct tcap_dialogue *td, struct TCMessage *tcmsg)
 {
+	struct End *endmsg = &tcmsg.choice.end;
+
 	switch (state) {
 	case ACTIVE:
-		if (dialogue) {
+		if (endmsg->dialoguePortion) {
 			/* Discard components */
 			/* TC-P-ABORT.ind to TCU */
 			rc = tcap_tcu_abort_ind(td, app_ctx_name, user_info);
@@ -199,7 +204,7 @@ int tcap_csl_tc_end_ind(struct tcap_dialogue *td)
 		return -EINVAL;
 	}
 
-	if (dialogue) {
+	if (endmsg->dialoguePortion) {
 		if (app_ctx_mode) {
 			/* Extract dialogue portion */
 			/* Is dialogue portion corect? */
@@ -209,7 +214,7 @@ int tcap_csl_tc_end_ind(struct tcap_dialogue *td)
 			}
 			/* TC-END.ind to TCU */
 			rc = tcap_tcu_end_ind(td, app_ctx_name, user_info, components);
-			if (components) {
+			if (endmsg->components) {
 				/* Components to CHA */
 			}
 	} else {
@@ -239,9 +244,11 @@ int tcap_csl_tr_notice_ind()
 	return tcap_tcu_notice_ind(td, cause);
 }
 
-/* TR-CONTONUE.ind from TSL */
-int tcap_csl_tr_continue_ind()
+/* TR-CONTINUE.ind from TSL */
+int tcap_csl_tr_continue_ind(struct TCMessage *tcmsg)
 {
+	struct Continue *ctmsg = &tcmsg->choice.Continue;
+
 	switch (state) {
 	case INIT_SENT:
 		break;
@@ -250,7 +257,7 @@ int tcap_csl_tr_continue_ind()
 		return -EINVAL;
 	}
 
-	if (dialogue) {
+	if (ctmsg->dialoguePortion) {
 		if (app_ctx_mode) {
 			/* Extract dialogue portion */
 			if (!correct) {
@@ -274,7 +281,7 @@ err_discard:
 	}
 	/* TC-CONTINUE.ind to TCU */
 	rc = tcap_tcu_cont_ind(td, app_ctx_name, user_info);
-	if (components) {
+	if (ctmsg->components) {
 		/* Components to CHA */
 	}
 	state = ACTIVE;
diff --git a/src/tcap.h b/src/tcap.h
index 537feb5..763ca07 100644
--- a/src/tcap.h
+++ b/src/tcap.h
@@ -23,7 +23,7 @@ struct tcap_dialogue {
 	/* global list of dialogues */
 	struct llist_head list;
 
-	/* Dialogue ID: Maps onto Transaction IDs */
+	/* Dialogue ID: Local significance; maps to Transaction IDs */
 	uint32_t dialogue_id;
 
 	/* private list of ISMs / Invocations in this dialogue */
@@ -42,6 +42,7 @@ enum tcap_invocation_state {
 	TCAP_IS_WAIT_REJECT,
 };
 
+#define TCAP_INV_LINKED_NONE	-1234
 struct tcap_invocation {
 	struct llist_head list;
 
@@ -54,6 +55,7 @@ struct tcap_invocation {
 	struct tcap_invocation_state state;
 
 	/* Invocation timer */
+	uint32_t inv_timeout;		/* Seconds */
 	struct bsc_timer inv_timer;
 	struct bsc_timer rej_timer;
 };
diff --git a/src/tsl_tsm.c b/src/tsl_tsm.c
index d520445..b131626 100644
--- a/src/tsl_tsm.c
+++ b/src/tsl_tsm.c
@@ -14,7 +14,7 @@ int tcap_tsm_begin_recv(struct tcap_transaction *tt, struct TCMessage *tcmsg)
 	/* FIXME: DHA */
 
 	/* FIXME: TR-BEGIN.ind to CSL */
-	tcap_csl_tc_begin_ind();
+	tcap_csl_tr_begin_ind();
 
 	tt->state = TCPA_TS_INIT_RECV;