diff --git a/openbsc/src/mgcp/mgcp_network.c b/openbsc/src/mgcp/mgcp_network.c
index 6ee268c..96f35df 100644
--- a/openbsc/src/mgcp/mgcp_network.c
+++ b/openbsc/src/mgcp/mgcp_network.c
@@ -174,7 +174,7 @@
 		return -1;
 	}
 
-	port = rtp_calculate_port(ENDPOINT_NUMBER(endp), 4000);
+	port = rtp_calculate_port(ENDPOINT_NUMBER(endp), cfg->transcoder_remote_base);
 	if (!is_rtp)
 		port += 1;