diff --git a/clock.c b/clock.c
index 8e7af0d..57683b9 100644
--- a/clock.c
+++ b/clock.c
@@ -470,7 +470,7 @@ static int clock_management_get_response(struct clock *c, struct port *p,
 	}
 	respond = clock_management_fill_response(c, p, req, rsp, id);
 	if (respond)
-		port_prepare_and_send(p, rsp, 0);
+		port_prepare_and_send(p, rsp, TRANS_GENERAL);
 	msg_put(rsp);
 	return respond;
 }
diff --git a/nsm.c b/nsm.c
index fb87b3a..0fb73fb 100644
--- a/nsm.c
+++ b/nsm.c
@@ -436,7 +436,7 @@ static int nsm_request(struct nsm *nsm, char *target)
 		pr_err("msg_pre_send failed");
 		goto out;
 	}
-	cnt = transport_sendto(nsm->trp, &nsm->fda, 1, msg);
+	cnt = transport_sendto(nsm->trp, &nsm->fda, TRANS_EVENT, msg);
 	if (cnt <= 0) {
 		pr_err("transport_sendto failed");
 		err = -1;
diff --git a/pmc_common.c b/pmc_common.c
index 9d21210..d1eafe7 100644
--- a/pmc_common.c
+++ b/pmc_common.c
@@ -160,7 +160,8 @@ static int pmc_send(struct pmc *pmc, struct ptp_message *msg)
 		pr_err("msg_pre_send failed");
 		return -1;
 	}
-	return transport_send(pmc->transport, &pmc->fdarray, 0, msg);
+	return transport_send(pmc->transport, &pmc->fdarray,
+			      TRANS_GENERAL, msg);
 }
 
 static int pmc_tlv_datalen(struct pmc *pmc, int id)
diff --git a/port.c b/port.c
index 1ff2e11..1757dfe 100644
--- a/port.c
+++ b/port.c
@@ -940,7 +940,7 @@ static int port_management_get_response(struct port *target,
 	}
 	respond = port_management_fill_response(target, rsp, id);
 	if (respond)
-		port_prepare_and_send(ingress, rsp, 0);
+		port_prepare_and_send(ingress, rsp, TRANS_GENERAL);
 	msg_put(rsp);
 	return respond;
 }
@@ -1297,7 +1297,7 @@ int port_delay_request(struct port *p)
 		msg->header.flagField[0] |= UNICAST;
 	}
 
-	if (port_prepare_and_send(p, msg, 1)) {
+	if (port_prepare_and_send(p, msg, TRANS_EVENT)) {
 		pr_err("port %hu: send delay request failed", portnum(p));
 		goto out;
 	}
@@ -1354,7 +1354,7 @@ static int port_tx_announce(struct port *p)
 		pr_err("port %hu: append path trace failed", portnum(p));
 	}
 
-	err = port_prepare_and_send(p, msg, 0);
+	err = port_prepare_and_send(p, msg, TRANS_GENERAL);
 	if (err) {
 		pr_err("port %hu: send announce failed", portnum(p));
 	}
@@ -1457,7 +1457,7 @@ static int port_tx_sync(struct port *p, struct address *dst)
 		goto out;
 	}
 
-	err = port_prepare_and_send(p, fup, 0);
+	err = port_prepare_and_send(p, fup, TRANS_GENERAL);
 	if (err) {
 		pr_err("port %hu: send follow up failed", portnum(p));
 	}
@@ -1758,7 +1758,7 @@ static int process_delay_req(struct port *p, struct ptp_message *m)
 		err = -1;
 		goto out;
 	}
-	err = port_prepare_and_send(p, msg, 0);
+	err = port_prepare_and_send(p, msg, TRANS_GENERAL);
 	if (err) {
 		pr_err("port %hu: send delay response failed", portnum(p));
 		goto out;
@@ -2533,18 +2533,19 @@ static enum fsm_event bc_event(struct port *p, int fd_index)
 int port_forward(struct port *p, struct ptp_message *msg)
 {
 	int cnt;
-	cnt = transport_send(p->trp, &p->fda, 0, msg);
+	cnt = transport_send(p->trp, &p->fda, TRANS_GENERAL, msg);
 	return cnt <= 0 ? -1 : 0;
 }
 
 int port_forward_to(struct port *p, struct ptp_message *msg)
 {
 	int cnt;
-	cnt = transport_sendto(p->trp, &p->fda, 0, msg);
+	cnt = transport_sendto(p->trp, &p->fda, TRANS_GENERAL, msg);
 	return cnt <= 0 ? -1 : 0;
 }
 
-int port_prepare_and_send(struct port *p, struct ptp_message *msg, int event)
+int port_prepare_and_send(struct port *p, struct ptp_message *msg,
+			  enum transport_event event)
 {
 	int cnt;
 
@@ -2658,7 +2659,7 @@ int port_management_error(struct PortIdentity pid, struct port *ingress,
 	mes->error = error_id;
 	mes->id = mgt->id;
 
-	err = port_prepare_and_send(ingress, msg, 0);
+	err = port_prepare_and_send(ingress, msg, TRANS_GENERAL);
 	msg_put(msg);
 	return err;
 }
diff --git a/port.h b/port.h
index a76b2bd..d828875 100644
--- a/port.h
+++ b/port.h
@@ -105,10 +105,10 @@ int port_forward_to(struct port *p, struct ptp_message *msg);
  * port_forward if you need to send single message to several ports.
  * @param p        A pointer previously obtained via port_open().
  * @param msg      The message to send.
- * @param event    0 if the message is a general message, 1 if it is an
- *                 event message.
+ * @param event    One of the @ref transport_event enumeration values.
  */
-int port_prepare_and_send(struct port *p, struct ptp_message *msg, int event);
+int port_prepare_and_send(struct port *p, struct ptp_message *msg,
+			  enum transport_event event);
 
 /**
  * Obtain a port's identity.