SIP NAT problem


I (ext 1114) have an extension 1512 which is outside my network but well connected using a VPN tunnel. 1512 can call 1114 and there a 2 way audio converstaion without any issue. The only problem I have is I cannot call ext 1512. When try calling 1512 it goes directly to its voicemail.

The log has been attached.

Any suggestions. Thanks!