You can not make a SIP to SIP call from SX 20 to C-20 without SIP registrar(CUCM) or H323 to SIP without a gatekeeper(VCS), However; if the C20 will be configured for H323 calling you can make H323 to H323 call using NAT.You can check out the SX20 ...
As per the above information its seems the C20 is configured for SIP. As number@domain name is SIP URI which you will dial to connect to C20. In that case it would be a H323 to SIP traversal call and both the endpoints should register with a gatekee...
Hi Shen,Please make sure if the you are making a Point to point Bothe the devices should be in the same network.If you are making a call to the public IP the NAT address should be configured on the endpoints.Please check the configuration for the C2...
