diff --git a/include/osmocom/bsc/bsc_msc_data.h b/include/osmocom/bsc/bsc_msc_data.h
index 4720845..1f9872a 100644
--- a/include/osmocom/bsc/bsc_msc_data.h
+++ b/include/osmocom/bsc/bsc_msc_data.h
@@ -191,5 +191,25 @@
 	return (port - base) / 2;
 }
 
+static inline bool msc_is_aoip(const struct bsc_msc_data *msc)
+{
+	switch (msc->a.asp_proto) {
+	case OSMO_SS7_ASP_PROT_SUA:
+	case OSMO_SS7_ASP_PROT_M3UA:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline bool msc_is_sccplite(const struct bsc_msc_data *msc)
+{
+	switch (msc->a.asp_proto) {
+	case OSMO_SS7_ASP_PROT_IPA:
+		return true;
+	default:
+		return false;
+	}
+}
 
 #endif
diff --git a/src/osmo-bsc/bsc_subscr_conn_fsm.c b/src/osmo-bsc/bsc_subscr_conn_fsm.c
index 87ad567..7b9f912 100644
--- a/src/osmo-bsc/bsc_subscr_conn_fsm.c
+++ b/src/osmo-bsc/bsc_subscr_conn_fsm.c
@@ -1058,14 +1058,7 @@
 	if (!conn || !conn->sccp.msc)
 		return false;
 
-	switch (conn->sccp.msc->a.asp_proto) {
-	case OSMO_SS7_ASP_PROT_SUA:
-	case OSMO_SS7_ASP_PROT_M3UA:
-		return true;
-
-	default:
-		return false;
-	}
+	return msc_is_aoip(conn->sccp.msc);
 }
 
 bool gscon_is_sccplite(struct gsm_subscriber_connection *conn)
@@ -1073,11 +1066,5 @@
 	if (!conn || !conn->sccp.msc)
 		return false;
 
-	switch (conn->sccp.msc->a.asp_proto) {
-	case OSMO_SS7_ASP_PROT_IPA:
-		return true;
-
-	default:
-		return false;
-	}
+	return msc_is_sccplite(conn->sccp.msc);
 }
diff --git a/src/osmo-bsc/osmo_bsc_sigtran.c b/src/osmo-bsc/osmo_bsc_sigtran.c
index 5d61c32..8303c4f 100644
--- a/src/osmo-bsc/osmo_bsc_sigtran.c
+++ b/src/osmo-bsc/osmo_bsc_sigtran.c
@@ -523,8 +523,7 @@
 		 * an X-Osmo-IGN flag telling osmo-mgw to ignore CallID mismatches for this endpoint.
 		 * If an explicit VTY command has already indicated whether or not to send X-Osmo-IGN, do
 		 * not overwrite that setting. */
-		if (msc->a.asp_proto == OSMO_SS7_ASP_PROT_IPA
-		    && !msc->x_osmo_ign_configured)
+		if (msc_is_sccplite(msc) && !msc->x_osmo_ign_configured)
 			msc->x_osmo_ign |= MGCP_X_OSMO_IGN_CALLID;
 
 		/* If unset, use default local SCCP address */