Hello List, Thanks to the help provided by Stanislav, I learned of issue #9113, https://freeswitch.org/jira/si/jira.issueviews:issue-html/FS-9113/FS-9113.ht..., which seems to be related to the issues I have been experiencing with FreeSWITCH, TLS and failed call setups. Coincidentally, or not, the fix pushed on that issue was aligned with whole months where I did not experience any TLS issues. Calls were going through fine, until all of a sudden they started failing again. This is on 2 distinct servers running a load balanced FS setup, and using Yealink phones. To sum up, here is what is going on. From the Yealink, calls with TLS work if I don't use SRTP. From the Yealink, calls crash if I use TLS and SRTP. From my laptop softphone, calls only crash sometimes if I use TLS and SRTP. How can I debug the TLS session on the FreeSWITCH side to see what happens with the TLS thread? I don't mean packet capture. I have a feeling that the packet size is too large and doesn't make it to the FS box intact after the 407 Proxy Required is received by the client. Here is the log for the Yealink: http://pastebin.com/smKP286x Your lights would be so appreciated, I'm losing my mind over this. Best, Emrah