[Serusers] Can 'avp_check' check whether sourceIP and destinationIP are the same subnet segment?

[Zen Kato]

If 2 UAs exist on the same network segment, e.g., 192.168.0.1 and 192.168.0.2,
how to check whether sourceIP and destinationIP are the same subnet segment 
using avpops module?

If 'ser' sits on 192.168.100.1, UA1 can send 'INVITE' then UA2 rings, but
when we pick up UA2's handset, these two UAs goes to a panic. I have to
reboot two UAs. So, I would like to 'rewritehostport' INVITE packets to 'man-in-the-middle-sip-server', 'asterisk' when UA1 INVITEs UA2.

    ser  asterisk
     |.1   |.2    192.168.100.0/24
   --------------------------------
           |.254
         router
           |.254   192.168.0.0/24
  ---------------------------------
    |.1            |.2
   UA1            UA2

Regards,

Zen