[Serusers] Does SER support virtual IP interfaces?

Hi, I've installed ser-0.8.11 on FreeBSD via ports. Things run fine on a private LAN. I have setup a pp2p tunnel, which shows up as ng1 in FreeBSD's ifconfig. This allows Windows users at the remote end of the tunnel to see the FreeBSD box just fine. The pp2p tunnel runs over a NAT'ed, public IP address to another box which does the same thing. However, NAT isn't (or shouldn't be) in the loop as the pp2p tunnel hides all this. The public internet looks like one p2p link. I've verified the above via tcpdump using many different applicationss. Private addresses are used on both LAN's. Any box can see any box just fine. On one FreeBSD machine, I am also running SER. It doesn't seem to respond to the register SIP message. SER is listening ONLY to the ip address that corresponds to its end of the pp2p tunnel. Before I dig into what I might be doing wrong, I'd like to know if the above is even supported. Thanks, MikeC