Xima released a new device a while ago, the VRTX.
The VRTX is used for recording calls on a SIP trunk or an E1/T1.
On the front there are two ports, one from the router (SIP) or ISDN Modem and the second for the IPOffice.
On the back there is an USB mini connector to connect the VRTX to a PC or server running Xima Chronicall.
The VRTX requires that Xima Chronicall is installed, see http://www.ipofficeassistance.com/installing-xima-chronicall/
Also required is the recording library license and a license per channel.
If you want to record 10 calls at the same time then 10 channels are needed.