It's ok that the source IP in the SDP body of the INVITE from brekeke to ATA2 be 10.0.0.157.
Perhaps you should try to change the RTP relay setting from "auto" to "on" in RTP Configuration.

you can try this

matching pattern
$registered=true

deploy pattern
$rtp=false

for all registered ua, rtp relay will be turned off.

Thank you for your reply.

No plug-in has been deployed in that case.

And I replace Brekeke Sip Server 2.0 with Brekeke Sip Server 2.1Beta, the problem has been solved.

1. Brekeke Product Name and version: sip server 2.0.7.2 2. Java version: j2se jre 5.0 3. OS type and the version: windows xp 4. UA (phone), gateway or other hardware/software involved: 5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/networkpatterns.html : 6. Your problem ...