Bug #2635
Updated by neels over 6 years ago
Typically, an OsmoBTS sends RTPC one port next to RTP, for example the voice stream comes from port 1234, where the RTPC Sender Report packets come from port poert 1235. When I set up OsmoBSC with its own OsmoMGW, I notice that both call legs consistently send the sender reports from unexpected ports. For example, here the RTP streams come from ports 33869 and 56820, while the RTPC come from 54110 and 52268: <pre> <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:22 data from wrong source port: 54110, expected: 33869 for RTP or 33870 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:22 packet tossed <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:21 data from wrong source port: 52268, expected: 56820 for RTP or 56821 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:21 packet tossed <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:22 data from wrong source port: 54110, expected: 33869 for RTP or 33870 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:22 packet tossed <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:21 data from wrong source port: 52268, expected: 56820 for RTP or 56821 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:21 packet tossed <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:22 data from wrong source port: 54110, expected: 33869 for RTP or 33870 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:22 packet tossed <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:850 endpoint:21 data from wrong source port: 52268, expected: 56820 for RTP or 56821 for RTCP <0000> ../../../../src/osmo-mgw/src/libosmo-mgcp/mgcp_network.c:855 endpoint:21 packet tossed </pre> I am not familiar enough to understand how this can happen. Does the OsmoBSC fail to tell the BTS which ports to use? Have we broken OsmoBTS recently to disregard the RTPC port constraint? The voice call works well, only the Sender Reports are all discarded instead of forwarded. Can you find out what causes this / whether this is expected / ...
