Dear, I am currently working on a project that the situation is similar to Hybrid SIPS encryption in below link as I think. http://wiki.freeswitch.org/wiki/SIP_TLS#Hybrid_Encryption  My actual situation is like this.  Since, the HuaWei Softswitch isn't support for SRTP, i suppose Freeswitch can be setup as an intermediary to do it which it will be look like this. IP-phone <-SRTP-> FS <-RTP-> HuaWei Softswitch. But I have no idea how to set it up with Freeswitch (I'm newbie in FS, I jumped into FS for less than a month). Could anyone give me some advice or direction if FS is capable to do it? Regard, Rush