diff --git a/openbsc/src/Makefile.am b/openbsc/src/Makefile.am
index 1d18475..cbc809d 100644
--- a/openbsc/src/Makefile.am
+++ b/openbsc/src/Makefile.am
@@ -17,7 +17,7 @@
 		input/misdn.c input/ipaccess.c \
 		talloc_ctx.c system_information.c rest_octets.c \
 		rtp_proxy.c bts_siemens_bs11.c bts_ipaccess_nanobts.c \
-		bts_unknown.c bsc_version.c
+		bts_unknown.c bsc_version.c bsc_api.c
 
 libmsc_a_SOURCES = gsm_subscriber.c db.c telnet_interface.c \
 		mncc.c gsm_04_08.c gsm_04_11.c transaction.c \
diff --git a/openbsc/src/bsc_api.c b/openbsc/src/bsc_api.c
new file mode 100644
index 0000000..b504752
--- /dev/null
+++ b/openbsc/src/bsc_api.c
@@ -0,0 +1,33 @@
+/* GSM 08.08 like API for OpenBSC. The bridge from MSC to BSC */
+
+/* (C) 2010 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <openbsc/bsc_api.h>
+#include <openbsc/abis_rsl.h>
+
+
+int gsm0808_submit_dtap(struct gsm_subscriber_connection *conn,
+			struct msgb *msg, int link_id)
+{
+	msg->lchan = conn->lchan;
+	msg->trx = msg->lchan->ts->trx;
+	return rsl_data_request(msg, link_id);
+}
diff --git a/openbsc/src/gsm_04_11.c b/openbsc/src/gsm_04_11.c
index 40b257d..b835679 100644
--- a/openbsc/src/gsm_04_11.c
+++ b/openbsc/src/gsm_04_11.c
@@ -122,16 +122,11 @@
 				   "GSM 04.11");
 }
 
-static int gsm411_sendmsg(struct msgb *msg, u_int8_t link_id)
+static int gsm411_sendmsg(struct gsm_subscriber_connection *conn, struct msgb *msg, u_int8_t link_id)
 {
-	if (msg->lchan)
-		msg->trx = msg->lchan->ts->trx;
-
-	msg->l3h = msg->data;
-
 	DEBUGP(DSMS, "GSM4.11 TX %s\n", hexdump(msg->data, msg->len));
-
-	return rsl_data_request(msg, link_id);
+	msg->l3h = msg->data;
+	return gsm0808_submit_dtap(conn, msg, link_id);
 }
 
 /* SMC TC1* is expired */
@@ -155,9 +150,6 @@
 	gh->proto_discr = trans->protocol | (trans->transaction_id<<4);
 	gh->msg_type = msg_type;
 
-	/* assign the outgoing lchan */
-	msg->lchan = trans->conn->lchan;
-
 	/* mobile originating */
 	switch (gh->msg_type) {
 	case GSM411_MT_CP_DATA:
@@ -180,7 +172,7 @@
 
 	DEBUGPC(DSMS, "trans=%x\n", trans->transaction_id);
 
-	return gsm411_sendmsg(msg, trans->sms.link_id);
+	return gsm411_sendmsg(trans->conn, msg, trans->sms.link_id);
 }
 
 /* Prefix msg with a RP-DATA header and send as CP-DATA */