[Freeswitch-users] Scale UP Freeswitch

Hi, I have one server running Freeswitch with some ISDN connections (via FreeTDM+Sangoma boards) and some SIP connections with service providers and customer. The usage of Freeswitch is as switching so it "bridge" each incoming call to a new outgoing call. SIP calls use G.729 and ISDN calls use ALaw for voice encoding. Now the number of call is grow up and also the CPU load is a little high so I have the necessity to scale UP my Freeswitch to handle more calls: what is the best way to do that? My first idea is to use a Sangoma D500 board to reduce the CPU load. Can be this a solution? There are different way to scale UP? Thanks in advance, Stephen