I am trying to make a (H.323/SIP) call from my Collaborate system to a third party system and I can't hear or see them, what could be the issue ?

I am trying to make a (H.323/SIP) call from my Collaborate system to a third party system and I can't hear or see them, what could be the issue ?

Open the ports required in your firewall, In the Settings>Advanced>Admin menu Disable H.264 High Profile,  In the Settings>Advanced>Admin menu set Encryption mode to none