Our IP telephony system is multi-site centre processing model. I have one centre CUCM, IP Phones are located at head office and some branches. Now I want to integrate voice recording solution with CallRex. I know that CallRex (or some other similar softwares like ASC..) gets call information and content by SPAN. But SPAN or RSPAN work by switchport and VLAN. I have only one Callrex server in head office. Is this any solution to record the phones in branches office over WAN? Thank you very much.