diff --git a/src/rspro_util.c b/src/rspro_util.c
index c312e42..d55bd30 100644
--- a/src/rspro_util.c
+++ b/src/rspro_util.c
@@ -155,3 +155,33 @@
 
 	return pdu;
 }
+
+RsproPDU_t *rspro_gen_TpduModem2Card(const ClientSlot_t *client, const BankSlot_t *bank,
+				     const uint8_t *tpdu, unsigned int tpdu_len)
+{
+	RsproPDU_t *pdu = CALLOC(1, sizeof(*pdu));
+	if (!pdu)
+		return NULL;
+	pdu->msg.present = RsproPDUchoice_PR_tpduModemToCard;
+	pdu->msg.choice.tpduModemToCard.fromClientSlot = *client;
+	pdu->msg.choice.tpduModemToCard.toBankSlot = *bank;
+	/* TODO: flags? */
+	OCTET_STRING_fromBuf(&pdu->msg.choice.tpduModemToCard.data, (const char *)tpdu, tpdu_len);
+
+	return pdu;
+}
+
+RsproPDU_t *rspro_gen_TpduCard2Modem(const BankSlot_t *bank, const ClientSlot_t *client,
+				     const uint8_t *tpdu, unsigned int tpdu_len)
+{
+	RsproPDU_t *pdu = CALLOC(1, sizeof(*pdu));
+	if (!pdu)
+		return NULL;
+	pdu->msg.present = RsproPDUchoice_PR_tpduCardToModem;
+	pdu->msg.choice.tpduCardToModem.fromBankSlot = *bank;
+	pdu->msg.choice.tpduCardToModem.toClientSlot = *client;
+	/* TODO: flags? */
+	OCTET_STRING_fromBuf(&pdu->msg.choice.tpduCardToModem.data, (const char *)tpdu, tpdu_len);
+
+	return pdu;
+}
diff --git a/src/rspro_util.h b/src/rspro_util.h
index 8590a1b..ddade5b 100644
--- a/src/rspro_util.h
+++ b/src/rspro_util.h
@@ -27,3 +27,7 @@
 RsproPDU_t *rspro_gen_ConfigClientReq(const ClientSlot_t *client, uint32_t ip, uint16_t port);
 RsproPDU_t *rspro_gen_SetAtrReq(uint16_t client_id, uint16_t slot_nr, const uint8_t *atr,
 				unsigned int atr_len);
+RsproPDU_t *rspro_gen_TpduModem2Card(const ClientSlot_t *client, const BankSlot_t *bank,
+				     const uint8_t *tpdu, unsigned int tpdu_len);
+RsproPDU_t *rspro_gen_TpduCard2Modem(const BankSlot_t *bank, const ClientSlot_t *client,
+				     const uint8_t *tpdu, unsigned int tpdu_len);