[Freeswitch-users] Sip Session Timer on the fly

Hi all, I would like to know, if there is a way to FS is "transparent" with SST ? Currently, you can activate or deactivate SST on profile: <param name="enable-timer" value="false / true"/> But I want if client use SST, FS sends it to the B leg, and if client doesn't use SST, FS doesn't send it. thanks in advance