4 files changed, 72 insertions, 2 deletions

diff --git a/include/osmo-bts/gsm_data_shared.h b/include/osmo-bts/gsm_data_shared.h
index 81cac3e3..f4fb7661 100644
--- a/include/osmo-bts/gsm_data_shared.h
+++ b/include/osmo-bts/gsm_data_shared.h
@@ -688,6 +688,11 @@ struct gsm_bts {
 	struct llist_head oml_queue;
 	unsigned int rtp_jitter_buf_ms;
 	bool rtp_jitter_adaptive;
+
+	uint16_t rtp_port_range_start;
+	uint16_t rtp_port_range_end;
+	uint16_t rtp_port_range_next;
+
 	struct {
 		uint8_t ciphers;	/* flags A5/1==0x1, A5/2==0x2, A5/3==0x4 */
 	} support;
diff --git a/src/common/bts.c b/src/common/bts.c
index 74630cc3..54e5480a 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -135,6 +135,9 @@ int bts_init(struct gsm_bts *bts)
 	bts->paging_state = paging_init(bts, 200, 0);
 	bts->ul_power_target = -75;	/* dBm default */
 	bts->rtp_jitter_adaptive = false;
+	bts->rtp_port_range_start = 16384;
+	bts->rtp_port_range_end = 17407;
+	bts->rtp_port_range_next = bts->rtp_port_range_start;
 
 	/* configurable via OML */
 	bts->load.ccch.load_ind_period = 112;
diff --git a/src/common/rsl.c b/src/common/rsl.c
index 5dd2c59f..b5d0c2b0 100644
--- a/src/common/rsl.c
+++ b/src/common/rsl.c
@@ -1787,6 +1787,29 @@ static char *get_rsl_local_ip(struct gsm_bts_trx *trx)
 	return hostbuf;
 }
 
+static int bind_rtp(struct gsm_bts *bts, struct osmo_rtp_socket *rs, const char *ip)
+{
+	int rc;
+	unsigned int i;
+	unsigned int tries;
+
+	tries = (bts->rtp_port_range_end - bts->rtp_port_range_start) / 2;
+	for (i = 0; i < tries; i++) {
+
+		if (bts->rtp_port_range_next >= bts->rtp_port_range_end)
+			bts->rtp_port_range_next = bts->rtp_port_range_start;
+
+		rc = osmo_rtp_socket_bind(rs, ip, bts->rtp_port_range_next);
+
+		bts->rtp_port_range_next += 2;
+
+		if (rc == 0)
+			return 0;
+	}
+
+	return -1;
+}
+
 static int rsl_rx_ipac_XXcx(struct msgb *msg)
 {
 	struct abis_rsl_dchan_hdr *dch = msgb_l2(msg);
@@ -1907,8 +1930,7 @@ static int rsl_rx_ipac_XXcx(struct msgb *msg)
 			 * back to the BSC in the CRCX_ACK */
 			ipstr = get_rsl_local_ip(lchan->ts->trx);
 		}
-		rc = osmo_rtp_socket_bind(lchan->abis_ip.rtp_socket,
-					  ipstr, -1);
+		rc = bind_rtp(bts, lchan->abis_ip.rtp_socket, ipstr);
 		if (rc < 0) {
 			LOGP(DRTP, LOGL_ERROR,
 			     "%s IPAC Failed to bind RTP/RTCP sockets\n",
diff --git a/src/common/vty.c b/src/common/vty.c
index 2716a7a7..60613352 100644
--- a/src/common/vty.c
+++ b/src/common/vty.c
@@ -262,6 +262,8 @@ static void config_write_bts_single(struct vty *vty, struct gsm_bts *bts)
 	if (bts->rtp_jitter_adaptive)
 		vty_out(vty, " adaptive");
 	vty_out(vty, "%s", VTY_NEWLINE);
+	vty_out(vty, " rtp port-range %u %u%s", bts->rtp_port_range_start,
+		bts->rtp_port_range_end, VTY_NEWLINE);
 	vty_out(vty, " paging queue-size %u%s", paging_get_queue_max(bts->paging_state),
 		VTY_NEWLINE);
 	vty_out(vty, " paging lifetime %u%s", paging_get_lifetime(bts->paging_state),
@@ -486,6 +488,43 @@ DEFUN(cfg_bts_rtp_jitbuf,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_bts_rtp_port_range,
+	cfg_bts_rtp_port_range_cmd,
+	"rtp port-range <1-65534> <1-65534>",
+      RTP_STR "Range of local ports to use for RTP/RTCP traffic\n")
+{
+	struct gsm_bts *bts = vty->index;
+	unsigned int start;
+	unsigned int end;
+
+	start = atoi(argv[0]);
+	end = atoi(argv[1]);
+
+	if (end < start) {
+		vty_out(vty, "range end port (%u) must be greater than the range start port (%u)!%s",
+			end, start, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (start & 1) {
+		vty_out(vty, "range must begin at an even port number! (%u not even)%s",
+			start, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if ((end & 1) == 0) {
+		vty_out(vty, "range must end at an odd port number! (%u not odd)%s",
+			end, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	bts->rtp_port_range_start = start;
+	bts->rtp_port_range_end = end;
+	bts->rtp_port_range_next = bts->rtp_port_range_start;
+
+	return CMD_SUCCESS;
+}
+
 #define PAG_STR "Paging related parameters\n"
 
 DEFUN(cfg_bts_paging_queue_size,
@@ -1554,6 +1593,7 @@ int bts_vty_init(struct gsm_bts *bts, const struct log_info *cat)
 	install_element(BTS_NODE, &cfg_bts_oml_ip_cmd);
 	install_element(BTS_NODE, &cfg_bts_rtp_bind_ip_cmd);
 	install_element(BTS_NODE, &cfg_bts_rtp_jitbuf_cmd);
+	install_element(BTS_NODE, &cfg_bts_rtp_port_range_cmd);
 	install_element(BTS_NODE, &cfg_bts_band_cmd);
 	install_element(BTS_NODE, &cfg_description_cmd);
 	install_element(BTS_NODE, &cfg_no_description_cmd);