Avaya IP office connection between two PBX

Job ID: 32607937

Budget: $15 – $25 USD

WE have VPN between two branches , and we have two Avaya IP office connected together ,we want someone to help us find the problem ,why site A can call Site B ,while site B cannot call site A ? please help ?
Related categories: Linux Asterisk PBX Cisco VoIP Network Administration