diff --git a/include/openbsc/msc_ifaces.h b/include/openbsc/msc_ifaces.h
index 83aad92..2965c72 100644
--- a/include/openbsc/msc_ifaces.h
+++ b/include/openbsc/msc_ifaces.h
@@ -22,7 +22,7 @@
  * the compiler complains about an undefined reference to iu_tx(). If you,
  * however, link against libiu as well as the osmo-iuh libs (etc.), iu_tx() is
  * available. A unit test may instead simply implement a dummy iu_tx() function
- * and not link against osmo-iuh.
+ * and not link against osmo-iuh, see tests/libiudummy/.
  */
 
 /* Each main linkage must implement this function (see comment above). */
@@ -35,6 +35,13 @@
  * " */
 extern int a_tx(struct msgb *msg);
 
+/* So far this is a dummy implemented in libmsc/a_iface.c. When A-interface
+ * gets implemented, it should be in a separate lib (like libiu), this function
+ * should move there, and the following comment should remain here: "
+ * Each main linkage must implement this function (see comment above).
+ * " */
+extern int a_page(const char *imsi, uint32_t tmsi, uint16_t lac);
+
 int msc_tx_dtap(struct gsm_subscriber_connection *conn,
 		struct msgb *msg);
 
@@ -45,3 +52,7 @@
 /* TODO: specific to A interface, move this away */
 int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
 			       const uint8_t *key, int len, int include_imeisv);
+
+int msc_tx_common_id(struct gsm_subscriber_connection *conn);
+int msc_call_assignment(struct gsm_trans *trans);
+int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2);