We are needing to create a SIP trunk to link our existing SV9100 with our new PBXact (FreePBX/Asterisk based) server. This SIP trunk will need to facilitate 2-way extension to extension dialing between the systems while we migrate all extensions from NEC to PBXact. I am familiar with creating SIP trunk and routing needed on the PBXact side, but not sure what exactly is needed on the NEC side.