The tsdelta computation and error detection didn't handle the
intialisation phase properly.

This patches fixes this by skipping the output timing validation
when the SSRCs don't match.

Sponsored-by: On-Waves ehf
---
 openbsc/src/libmgcp/mgcp_network.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/openbsc/src/libmgcp/mgcp_network.c 
b/openbsc/src/libmgcp/mgcp_network.c
index 75d39c1..06452a6 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -237,6 +237,15 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp, 
struct mgcp_rtp_state *sta
                state->jitter = 0;
                state->transit = arrival_time - timestamp;
                state->out_stream = state->in_stream;
+               state->out_stream.last_timestamp = timestamp;
+               state->out_stream.ssrc = rtp_hdr->ssrc - 1; /* SSRC change <=> 
initialisation */
+               LOGP(DMGCP, LOGL_INFO,
+                       "Initializing stream on 0x%x SSRC: %u timestamp: %u "
+                       "from %s:%d in %d\n",
+                       ENDPOINT_NUMBER(endp), state->in_stream.ssrc,
+                       state->seq_offset,
+                       inet_ntoa(addr->sin_addr), ntohs(addr->sin_port),
+                       endp->conn_mode);
        } else if (state->in_stream.ssrc != rtp_hdr->ssrc) {
                int32_t tsdelta = state->out_stream.last_tsdelta;
                if (tsdelta == 0) {
@@ -286,9 +295,10 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp, 
struct mgcp_rtp_state *sta
        }
 
        /* Check again, whether the timestamps are still valid */
-       check_rtp_timestamp(endp, &state->out_stream, rtp_end, addr,
-                           seq, timestamp, "output",
-                           &state->out_stream.last_tsdelta);
+       if (state->out_stream.ssrc == rtp_hdr->ssrc)
+               check_rtp_timestamp(endp, &state->out_stream, rtp_end, addr,
+                                   seq, timestamp, "output",
+                                   &state->out_stream.last_tsdelta);
 
        /*
         * The below takes the shape of the validation from Appendix A. Check
-- 
1.7.9.5


Reply via email to