SIP SBC
From Yate Documentation
Yate can be used as a SIP session border controller providing security for the internal network of the carrier. It provides also NAT traversal support.
To enable this feature you have to add in ysipchan.conf:
[general] ignorevia=yes
If you want to use RTP forward between the 2 endpoints you can setup in regexroute.conf something like:
${rtp_forward}possible=;rtp_forward=yes