As a DTLS server, RTP engine should retransmit the last flight to client if the last flight is lost on network.
Unexpected behaviour you saw
As a DTLS server, RTP engine does not retransmit the last flight to client if the last flight is lost on network.
That will cause DTLS handshake failure.
Steps to reproduce the problem
Use an openssl as client, build DTLS connection with RTP engine, and set packet lost to 30% from RTP engine to client.
sometimes, DTLS handshake cannot be built correctly.
Additional program output to the terminal or logs illustrating the issue
Same issue with detailed description: https://github.com/pion/dtls/issues/479
Anything else?
It is easily to fix this issue, RTPengine cache the last flight (type == SSL3_MT_NEWSESSION_TICKET) before sending to client, if client re-sends the last DTLS message to RTP engine, RTP engine can retransmit the cached last flight to client.
rtpengine version the issue has been seen with
No response
Used distribution and its version
No response
Linux kernel version used
No response
CPU architecture issue was seen on (see
uname -m)None
Expected behaviour you didn't see
As a DTLS server, RTP engine should retransmit the last flight to client if the last flight is lost on network.
Unexpected behaviour you saw
As a DTLS server, RTP engine does not retransmit the last flight to client if the last flight is lost on network. That will cause DTLS handshake failure.
Steps to reproduce the problem
Use an openssl as client, build DTLS connection with RTP engine, and set packet lost to 30% from RTP engine to client. sometimes, DTLS handshake cannot be built correctly.
Additional program output to the terminal or logs illustrating the issue
Anything else?
It is easily to fix this issue, RTPengine cache the last flight (type == SSL3_MT_NEWSESSION_TICKET) before sending to client, if client re-sends the last DTLS message to RTP engine, RTP engine can retransmit the cached last flight to client.