path: root/openbsc
diff options
authorNeels Hofmeyr <nhofmeyr@sysmocom.de>2016-10-21 01:35:57 +0200
committerNeels Hofmeyr <nhofmeyr@sysmocom.de>2017-03-09 17:47:17 +0100
commitd3d62f4d40bfe204adebb646375da41ccf04ced7 (patch)
tree4f8e50561dfe73c4a737c113034c881cea1acfb9 /openbsc
parentffe25438149557fe7cb7a164dfec7380f91d7343 (diff)
mgcp: hack RAB success from nano3G: patch first RTP payloadneels/issue_1978
The ip.access nano3G needs the first RTP payload's first two bytes to read hex 'e400', or it will reject the RAB assignment. Add flag patched_first_rtp_payload to mgcp_rtp_state to detect the first RTP payload on a stream, and overwrite its first bytes with e400. This should probably be configurable, but seems to not harm other femto cells (as long as we patch only the first RTP payload in each stream). Only do this when sending to the BTS side. Change-Id: If0887b0b7714fc204f2addab2d43d44bb283ba21
Diffstat (limited to 'openbsc')
2 files changed, 10 insertions, 0 deletions
diff --git a/openbsc/include/openbsc/mgcp_internal.h b/openbsc/include/openbsc/mgcp_internal.h
index b58eb9b5..4e215b8f 100644
--- a/openbsc/include/openbsc/mgcp_internal.h
+++ b/openbsc/include/openbsc/mgcp_internal.h
@@ -64,6 +64,7 @@ struct mgcp_rtp_state {
uint32_t stats_jitter;
int32_t stats_transit;
int stats_cycles;
+ bool patched_first_rtp_payload;
struct mgcp_rtp_codec {
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index 5686e594..b64e25dd 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -666,6 +666,14 @@ int mgcp_send(struct mgcp_endpoint *endp, int dest, int is_rtp,
forward_data(rtp_end->rtp.fd, &endp->taps[tap_idx],
buf, len);
+ if (tap_idx == MGCP_TAP_BTS_OUT
+ && !rtp_state->patched_first_rtp_payload) {
+ uint8_t *data = &buf[12];
+ osmo_hexparse("e400", data, 2);
+ rtp_state->patched_first_rtp_payload = true;
+ }
rc = mgcp_udp_send(rtp_end->rtp.fd,
rtp_end->rtp_port, buf, len);
@@ -685,6 +693,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int dest, int is_rtp,
return mgcp_udp_send(rtp_end->rtcp.fd,
rtp_end->rtcp_port, buf, rc);