[SR-Users] "Discarded invalid SRTP packet: authentication failed" warning

Hello, We're having an issue with rtpengine (used by Kamailio) where audio works initially, but then after an apparently random amount of time stop working. We see that when audio stops working rtpengine logs this: Dec 10 09:58:57 hostname rtpengine[376]: WARNING: [Pl1SeGDssOsDNWQdvey4lg.. port 48766]: Discarded invalid SRTP packet: authentication failed It then logs similar messages until the call hangs up. No such messages were logged while audio was working. Searching for this error message suggests that a change in the SSRC can cause the problem, but we don't see any such change in the PCAP. The source IP, port, codec, and SSRC all stay the same, and the Sequence increments as normal. Does anyone have suggestions on where to look next? We can share the PCAP privately if that would help anyone. Thanks for any advice! -- David Cunningham, Voisonics Limited http://voisonics.com/ USA: +1 213 221 1092 New Zealand: +64 (0)28 2558 3782