I just install the SER on Sun Solaris 8 with a Cisco AS5300 gateway do PSTN.
 
Between SIP phones all work's fine, but connections between SIP phones and the gateway (both directions) are dropped after 20 seconds.
 
I'm newbie on SER, anyone can help me to fix this behavior.
 
Regards,
 
José Ricardo Maia Moraes