I suspect that no one here has ever tried it. The docs say that it supports SIP, which is good. They also say it has two FXS ports. That being the case, the device essentially two "phones" so you'd need to assign SIP credentials from the FreeSWITCH directory (conf/directory/default/10xx.xml is a good place to start) to each port on the Cisco. As for how to configure the VG202 itself I think you're on your own. I googled around and didn't find much, even for people who may have tried it with Asterisk. All I found was one
reference to an issue someone was having with early media.
Let us know if you get it working - we'd appreciate you adding the knowledge to the FreeSWITCH wiki.